…lvm#144097)

In Aya/Rust, BPF map definitions are nested in two nested types:

* A struct representing the map type (e.g., `HashMap`, `RingBuf`) that
provides methods for interacting with the map type (e.g. `HashMap::get`,
`RingBuf::reserve`).
* An `UnsafeCell`, which informs the Rust compiler that the type is
thread-safe and can be safely mutated even as a global variable. The
kernel guarantees map operation safety.

This leads to a type hierarchy like:

```rust
    pub struct HashMap<K, V, const M: usize, const F: usize = 0>(
        core::cell::UnsafeCell<HashMapDef<K, V, M, F>>,
    );
    const BPF_MAP_TYPE_HASH: usize = 1;
    pub struct HashMapDef<K, V, const M: usize, const F: usize = 0> {
        r#type: *const [i32; BPF_MAP_TYPE_HASH],
        key: *const K,
        value: *const V,
        max_entries: *const [i32; M],
        map_flags: *const [i32; F],
    }
```

Then used in the BPF program code as a global variable:

```rust
    #[link_section = ".maps"]
    static HASH_MAP: HashMap<u32, u32, 1337> = HashMap::new();
```

Which is an equivalent of the following BPF map definition in C:

```c
    #define BPF_MAP_TYPE_HASH 1
    struct {
        int (*type)[BPF_MAP_TYPE_HASH];
        typeof(int) *key;
        typeof(int) *value;
        int (*max_entries)[1337];
    } map_1 __attribute__((section(".maps")));
```

Accessing the actual map definition requires traversing:

```
  HASH_MAP -> __0 -> value
```

Previously, the BPF backend only visited the pointee types of the
outermost struct, and didn’t descend into inner wrappers. This caused
issues when the key/value types were custom structs:

```rust
    // Define custom structs for key and values.
    pub struct MyKey(u32);
    pub struct MyValue(u32);

    #[link_section = ".maps"]
    #[export_name = "HASH_MAP"]
    pub static HASH_MAP: HashMap<MyKey, MyValue, 10> = HashMap::new();
```

These types weren’t fully visited and appeared in BTF as forward
declarations:

```
    llvm#30: <FWD> 'MyKey' kind:struct
    llvm#31: <FWD> 'MyValue' kind:struct
```

The fix is to enhance `visitMapDefType` to recursively visit inner
composite members. If a member is a composite type (likely a wrapper),
it is now also visited using `visitMapDefType`, ensuring that the
pointee types of the innermost stuct members, like `MyKey` and
`MyValue`, are fully resolved in BTF.

With this fix, the correct BTF entries are emitted:

```
    #6: <STRUCT> 'MyKey' sz:4 n:1
            #00 '__0' off:0 --> [7]
    llvm#7: <INT> 'u32' bits:32 off:0
    llvm#8: <PTR> --> [9]
    llvm#9: <STRUCT> 'MyValue' sz:4 n:1
            #00 '__0' off:0 --> [7]
```

Fixes: llvm#143361

The function already exposes a work list to avoid deep recursion, this
commit starts utilizing it in a helper that could also lead to a deep
recursion.

We have observed this crash on `clang/test/C/C99/n590.c` with our
internal builds that enable aggressive optimizations and hit the limit
earlier than default release builds of Clang.

See the added test for an example with a deeper recursion that used to
crash in upstream Clang before this change with the following stack
trace:

```
  #0 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /usr/local/google/home/ibiryukov/code/llvm-project/llvm/lib/Support/Unix/Signals.inc:804:13
  #1 llvm::sys::RunSignalHandlers() /usr/local/google/home/ibiryukov/code/llvm-project/llvm/lib/Support/Signals.cpp:106:18
  #2 SignalHandler(int, siginfo_t*, void*) /usr/local/google/home/ibiryukov/code/llvm-project/llvm/lib/Support/Unix/Signals.inc:0:3
  #3 (/lib/x86_64-linux-gnu/libc.so.6+0x3fdf0)
  #4 AnalyzeImplicitConversions(clang::Sema&, clang::Expr*, clang::SourceLocation, bool) /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12772:0
  #5 CheckCommaOperand /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:0:3
  #6 AnalyzeImplicitConversions /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12644:7
  llvm#7 AnalyzeImplicitConversions(clang::Sema&, clang::Expr*, clang::SourceLocation, bool) /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12776:5
  llvm#8 CheckCommaOperand /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:0:3
  llvm#9 AnalyzeImplicitConversions /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12644:7
 llvm#10 AnalyzeImplicitConversions(clang::Sema&, clang::Expr*, clang::SourceLocation, bool) /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12776:5
 llvm#11 CheckCommaOperand /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:0:3
 llvm#12 AnalyzeImplicitConversions /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12644:7
 llvm#13 AnalyzeImplicitConversions(clang::Sema&, clang::Expr*, clang::SourceLocation, bool) /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12776:5
 llvm#14 CheckCommaOperand /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:0:3
 llvm#15 AnalyzeImplicitConversions /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12644:7
 llvm#16 AnalyzeImplicitConversions(clang::Sema&, clang::Expr*, clang::SourceLocation, bool) /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12776:5
 llvm#17 CheckCommaOperand /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:0:3
 llvm#18 AnalyzeImplicitConversions /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12644:7
 llvm#19 AnalyzeImplicitConversions(clang::Sema&, clang::Expr*, clang::SourceLocation, bool) /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12776:5
... 700+ more stack frames.
```

## Problem

When the new setting

```
set target.parallel-module-load true
```
was added, lldb began fetching modules from the devices from multiple
threads simultaneously. This caused crashes of lldb when debugging on
android devices.

The top of the stack in the crash look something like this:
```
#0 0x0000555aaf2b27fe llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/llvm/bin/lldb-dap+0xb87fe)
 #1 0x0000555aaf2b0a99 llvm::sys::RunSignalHandlers() (/opt/llvm/bin/lldb-dap+0xb6a99)
 #2 0x0000555aaf2b2fda SignalHandler(int, siginfo_t*, void*) (/opt/llvm/bin/lldb-dap+0xb8fda)
 #3 0x00007f9c02444560 __restore_rt /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/signal/../sysdeps/unix/sysv/linux/libc_sigaction.c:13:0
 #4 0x00007f9c04ea7707 lldb_private::ConnectionFileDescriptor::Disconnect(lldb_private::Status*) (usr/bin/../lib/liblldb.so.15+0x22a7707)
 #5 0x00007f9c04ea5b41 lldb_private::ConnectionFileDescriptor::~ConnectionFileDescriptor() (usr/bin/../lib/liblldb.so.15+0x22a5b41)
 #6 0x00007f9c04ea5c1e lldb_private::ConnectionFileDescriptor::~ConnectionFileDescriptor() (usr/bin/../lib/liblldb.so.15+0x22a5c1e)
 llvm#7 0x00007f9c052916ff lldb_private::platform_android::AdbClient::SyncService::Stat(lldb_private::FileSpec const&, unsigned int&, unsigned int&, unsigned int&) (usr/bin/../lib/liblldb.so.15+0x26916ff)
 llvm#8 0x00007f9c0528b9dc lldb_private::platform_android::PlatformAndroid::GetFile(lldb_private::FileSpec const&, lldb_private::FileSpec const&) (usr/bin/../lib/liblldb.so.15+0x268b9dc)
```
Our workaround was to set `set target.parallel-module-load ` to `false`
to avoid the crash.

## Background

PlatformAndroid creates two different classes with one stateful adb
connection shared between the two -- one through AdbClient and another
through AdbClient::SyncService. The connection management and state is
complex, and seems to be responsible for the segfault we are seeing. The
AdbClient code resets these connections at times, and re-establishes
connections if they are not active. Similarly, PlatformAndroid caches
its SyncService, which uses an AdbClient class, but the SyncService puts
its connection into a different 'sync' state that is incompatible with a
standard connection.

## Changes in this diff

* This diff refactors the code to (hopefully) have clearer ownership of
the connection, clearer separation of AdbClient and SyncService by
making a new class for clearer separations of concerns, called
AdbSyncService.
* New unit tests are added
* Additional logs were added (see
llvm#145382 (comment)
for details)

…namic (llvm#153420)

Canonicalizing the following IR:

```
func.func @mul_zero_dynamic_nofold(%arg0: tensor<?x17xf32>) -> tensor<?x17xf32> {
  %0 = "tosa.const"() <{values = dense<0.000000e+00> : tensor<1x1xf32>}> : () -> tensor<1x1xf32>
  %1 = "tosa.const"() <{values = dense<0> : tensor<1xi8>}> : () -> tensor<1xi8>
  %2 = tosa.mul %arg0, %0, %1 : (tensor<?x17xf32>, tensor<1x1xf32>, tensor<1xi8>) -> tensor<?x17xf32>
  return %2 : tensor<?x17xf32>
}
```

resulted in a crash

```
#0 0x000056513187e8db backtrace (./build-release/bin/mlir-opt+0x9d698db)                                                                                                                                                                                                                                                                                                                   
 #1 0x0000565131b17737 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/llvm/lib/Support/Unix/Signals.inc:838:8                                                                                                                                                                                                                
 #2 0x0000565131b187f3 PrintStackTraceSignalHandler(void*) /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/llvm/lib/Support/Unix/Signals.inc:918:1                                                                                                                                                                                                                                
 #3 0x0000565131b18c30 llvm::sys::RunSignalHandlers() /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/llvm/lib/Support/Signals.cpp:105:18                                                                                                                                                                                                                                         
 #4 0x0000565131b18c30 SignalHandler(int, siginfo_t*, void*) /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/llvm/lib/Support/Unix/Signals.inc:409:3                                                                                                                                                                                                                              
 #5 0x00007f2e4165b050 (/lib/x86_64-linux-gnu/libc.so.6+0x3c050)                                                                                                                                                                                                                                                                                                                            
 #6 0x00007f2e416a9eec __pthread_kill_implementation ./nptl/pthread_kill.c:44:76                                                                                                                                                                                                                                                                                                            
 llvm#7 0x00007f2e4165afb2 raise ./signal/../sysdeps/posix/raise.c:27:6                                                                                                                                                                                                                                                                                                                         
 llvm#8 0x00007f2e41645472 abort ./stdlib/abort.c:81:7                                                                                                                                                                                                                                                                                                                                          
 llvm#9 0x00007f2e41645395 _nl_load_domain ./intl/loadmsgcat.c:1177:9                                                                                                                                                                                                                                                                                                                           
llvm#10 0x00007f2e41653ec2 (/lib/x86_64-linux-gnu/libc.so.6+0x34ec2)                                                                                                                                                                                                                                                                                                                            
llvm#11 0x00005651443ec4ba mlir::DenseIntOrFPElementsAttr::getRaw(mlir::ShapedType, llvm::ArrayRef<char>) /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/mlir/lib/IR/BuiltinAttributes.cpp:1361:3                                                                                                                                                                                    
llvm#12 0x00005651443f1209 mlir::DenseElementsAttr::resizeSplat(mlir::ShapedType) /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/mlir/lib/IR/BuiltinAttributes.cpp:0:10                                                                                                                                                                                                              
llvm#13 0x000056513f76f2b6 mlir::tosa::MulOp::fold(mlir::tosa::MulOpGenericAdaptor<llvm::ArrayRef<mlir::Attribute>>) /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/mlir/lib/Dialect/Tosa/IR/TosaCanonicalizations.cpp:0:0
```

from the folder for `tosa::mul` since the zero value was being reshaped
to `?x17` size which isn't supported. AFAIK, `tosa.const` requires all
dimensions to be static. So in this case, the fix is to not to fold the
op.

Reverts llvm#154949 due to suspected buildbot breakage
(https://lab.llvm.org/buildbot/#/builders/55/builds/16630/steps/11/logs/stdio).
Previously commented on the original pull request:
llvm#154949 (comment)

```
******************** TEST 'MLIR :: Dialect/XeGPU/subgroup-distribute.mlir' FAILED ********************
...
# | PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
# | Stack dump:
# | 0.	Program arguments: /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm_build_hwasan/bin/mlir-opt -xegpu-subgroup-distribute -allow-unregistered-dialect -canonicalize -cse -split-input-file /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/mlir/test/Dialect/XeGPU/subgroup-distribute.mlir
# |  #0 0x0000c0af4b066df0 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/lib/Support/Unix/Signals.inc:834:13
# |  #1 0x0000c0af4b060e20 llvm::sys::RunSignalHandlers() /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/lib/Support/Signals.cpp:105:18
# |  #2 0x0000c0af4b0691b4 SignalHandler(int, siginfo_t*, void*) /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/llvm/lib/Support/Unix/Signals.inc:426:38
# |  #3 0x0000ee25a3dcb8f8 (linux-vdso.so.1+0x8f8)
# |  #4 0x0000ee25a36c7608 (/lib/aarch64-linux-gnu/libc.so.6+0x87608)
# |  #5 0x0000ee25a367cb3c raise (/lib/aarch64-linux-gnu/libc.so.6+0x3cb3c)
# |  #6 0x0000ee25a3667e00 abort (/lib/aarch64-linux-gnu/libc.so.6+0x27e00)
# |  llvm#7 0x0000c0af4ae7e4b0 __sanitizer::Atexit(void (*)()) /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_posix_libcdep.cpp:168:10
# |  llvm#8 0x0000c0af4ae7c354 __sanitizer::Die() /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_termination.cpp:52:5
# |  llvm#9 0x0000c0af4ae66a30 Unlock /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/compiler-rt/lib/hwasan/../sanitizer_common/sanitizer_mutex.h:250:16
# | llvm#10 0x0000c0af4ae66a30 ~GenericScopedLock /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/compiler-rt/lib/hwasan/../sanitizer_common/sanitizer_mutex.h:386:51
# | llvm#11 0x0000c0af4ae66a30 __hwasan::ScopedReport::~ScopedReport() /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/compiler-rt/lib/hwasan/hwasan_report.cpp:54:5
# | llvm#12 0x0000c0af4ae661b8 __hwasan::(anonymous namespace)::BaseReport::~BaseReport() /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/compiler-rt/lib/hwasan/hwasan_report.cpp:477:7
# | llvm#13 0x0000c0af4ae63f5c __hwasan::ReportTagMismatch(__sanitizer::StackTrace*, unsigned long, unsigned long, bool, bool, unsigned long*) /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/compiler-rt/lib/hwasan/hwasan_report.cpp:1094:1
# | llvm#14 0x0000c0af4ae4f8e0 Destroy /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/compiler-rt/lib/hwasan/../sanitizer_common/sanitizer_common.h:532:31
# | llvm#15 0x0000c0af4ae4f8e0 ~InternalMmapVector /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/compiler-rt/lib/hwasan/../sanitizer_common/sanitizer_common.h:642:56
# | llvm#16 0x0000c0af4ae4f8e0 __hwasan::HandleTagMismatch(__hwasan::AccessInfo, unsigned long, unsigned long, void*, unsigned long*) /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/compiler-rt/lib/hwasan/hwasan.cpp:245:1
# | llvm#17 0x0000c0af4ae51e8c __hwasan_tag_mismatch4 /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/compiler-rt/lib/hwasan/hwasan.cpp:764:1
# | llvm#18 0x0000c0af4ae67b30 __interception::InterceptFunction(char const*, unsigned long*, unsigned long, unsigned long) /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/compiler-rt/lib/interception/interception_linux.cpp:60:0
# | llvm#19 0x0000c0af5641cd24 getNumResults /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/mlir/include/mlir/IR/Operation.h:404:37
# | llvm#20 0x0000c0af5641cd24 getOpResultImpl /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/mlir/include/mlir/IR/Operation.h:1010:5
# | llvm#21 0x0000c0af5641cd24 getResult /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/mlir/include/mlir/IR/Operation.h:407:54
# | llvm#22 0x0000c0af5641cd24 mlir::OpTrait::detail::MultiResultTraitBase<mlir::gpu::WarpExecuteOnLane0Op, mlir::OpTrait::VariadicResults>::getResult(unsigned int) /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/mlir/include/mlir/IR/OpDefinition.h:638:62
# | llvm#23 0x0000c0af56426b60 getType /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/mlir/include/mlir/IR/Value.h:63:33
# | llvm#24 0x0000c0af56426b60 getType /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/mlir/include/mlir/IR/Value.h:105:39
# | llvm#25 0x0000c0af56426b60 (anonymous namespace)::LoadDistribution::matchAndRewrite(mlir::gpu::WarpExecuteOnLane0Op, mlir::PatternRewriter&) const /home/b/sanitizer-aarch64-linux-bootstrap-hwasan/build/llvm-project/mlir/lib/Dialect/XeGPU/Transforms/XeGPUSubgroupDistribute.cpp:991:55
...
```

**Mitigation for:** google/sanitizers#749

**Disclosure:** I'm not an ASan compiler expert yet (I'm trying to
learn!), I primarily work in the runtime. Some of this PR was developed
with the help of AI tools (primarily as a "fuzzy `grep` engine"), but
I've manually refined and tested the output, and can speak for every
line. In general, I used it only to orient myself and for
"rubberducking".

**Context:**

The msvc ASan team (👋 ) has received an internal request to improve
clang's exception handling under ASan for Windows. Namely, we're
interested in **mitigating** this bug:
google/sanitizers#749

To summarize, today, clang + ASan produces a false-positive error for
this program:

```C++
#include <cstdio>
#include <exception>
int main()
{
	try	{
		throw std::exception("test");
	}catch (const std::exception& ex){
		puts(ex.what());
	}
	return 0;
}
```

The error reads as such:


```
C:\Users\dajusto\source\repros\upstream>type main.cpp
#include <cstdio>
#include <exception>
int main()
{
        try     {
                throw std::exception("test");
        }catch (const std::exception& ex){
                puts(ex.what());
        }
        return 0;
}
C:\Users\dajusto\source\repros\upstream>"C:\Users\dajusto\source\repos\llvm-project\build.runtimes\bin\clang.exe" -fsanitize=address -g -O0 main.cpp

C:\Users\dajusto\source\repros\upstream>a.exe
=================================================================
==19112==ERROR: AddressSanitizer: access-violation on unknown address 0x000000000000 (pc 0x7ff72c7c11d9 bp 0x0080000ff960 sp 0x0080000fcf50 T0)
==19112==The signal is caused by a READ memory access.
==19112==Hint: address points to the zero page.
    #0 0x7ff72c7c11d8 in main C:\Users\dajusto\source\repros\upstream\main.cpp:8
    #1 0x7ff72c7d479f in _CallSettingFrame C:\repos\msvc\src\vctools\crt\vcruntime\src\eh\amd64\handlers.asm:49
    #2 0x7ff72c7c8944 in __FrameHandler3::CxxCallCatchBlock(struct _EXCEPTION_RECORD *) C:\repos\msvc\src\vctools\crt\vcruntime\src\eh\frame.cpp:1567
    #3 0x7ffb4a90e3e5  (C:\WINDOWS\SYSTEM32\ntdll.dll+0x18012e3e5)
    #4 0x7ff72c7c1128 in main C:\Users\dajusto\source\repros\upstream\main.cpp:6
    #5 0x7ff72c7c33db in invoke_main C:\repos\msvc\src\vctools\crt\vcstartup\src\startup\exe_common.inl:78
    #6 0x7ff72c7c33db in __scrt_common_main_seh C:\repos\msvc\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288
    llvm#7 0x7ffb49b05c06  (C:\WINDOWS\System32\KERNEL32.DLL+0x180035c06)
    llvm#8 0x7ffb4a8455ef  (C:\WINDOWS\SYSTEM32\ntdll.dll+0x1800655ef)

==19112==Register values:
rax = 0  rbx = 80000ff8e0  rcx = 27d76d00000  rdx = 80000ff8e0
rdi = 80000fdd50  rsi = 80000ff6a0  rbp = 80000ff960  rsp = 80000fcf50
r8  = 100  r9  = 19930520  r10 = 8000503a90  r11 = 80000fd540
r12 = 80000fd020  r13 = 0  r14 = 80000fdeb8  r15 = 0
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: access-violation C:\Users\dajusto\source\repros\upstream\main.cpp:8 in main
==19112==ABORTING
```

The root of the issue _appears to be_ that ASan's instrumentation is
incompatible with Window's assumptions for instantiating `catch`-block's
parameters (`ex` in the snippet above).

The nitty gritty details are lost on me, but I understand that to make
this work without loss of ASan coverage, a "serious" refactoring is
needed. In the meantime, users risk false positive errors when pairing
ASan + catch-block parameters on Windows.

**To mitigate this** I think we should avoid instrumenting catch-block
parameters on Windows. It appears to me this is as "simple" as marking
catch block parameters as "uninteresting" in
`AddressSanitizer::isInterestingAlloca`. My manual tests seem to confirm
this.

I believe this is strictly better than today's status quo, where the
runtime generates false positives. Although we're now explicitly
choosing to instrument less, the benefit is that now more programs can
run with ASan without _funky_ macros that disable ASan on exception
blocks.

**This PR:** implements the mitigation above, and creates a simple new
test for it.

_Thanks!_

---------

Co-authored-by: Antonio Frighetto <[email protected]>