Auto merge of #122338 - workingjubilee:rollup-xzpt4v4, r=workingjubilee

Rollup of 15 pull requests

Successful merges:

 - #116791 (Allow codegen backends to opt-out of parallel codegen)
 - #116793 (Allow targets to override default codegen backend)
 - #117458 (LLVM Bitcode Linker: A self contained linker for nvptx and other targets)
 - #119385 (Fix type resolution of associated const equality bounds (take 2))
 - #121438 (std support for wasm32 panic=unwind)
 - #121893 (Add tests (and a bit of cleanup) for interior mut handling in promotion and const-checking)
 - #122080 (Clarity improvements to `DropTree`)
 - #122152 (Improve diagnostics for parenthesized type arguments)
 - #122166 (Remove the unused `field_remapping` field from `TypeLowering`)
 - #122249 (interpret: do not call machine read hooks during validation)
 - #122299 (Store backtrace for `must_produce_diag`)
 - #122318 (Revision-related tweaks for next-solver tests)
 - #122320 (Use ptradd for vtable indexing)
 - #122328 (unix_sigpipe: Replace `inherit` with `sig_dfl` in syntax tests)
 - #122330 (bootstrap readme: fix, improve, update)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

tests/pass/alloc-access-tracking.rs

@@ -0,0 +1,25 @@
+#![feature(start)]
+#![no_std]
+//@compile-flags: -Zmiri-track-alloc-id=17 -Zmiri-track-alloc-accesses -Cpanic=abort
+//@only-target-linux: alloc IDs differ between OSes for some reason
+
+extern "Rust" {
+    fn miri_alloc(size: usize, align: usize) -> *mut u8;
+    fn miri_dealloc(ptr: *mut u8, size: usize, align: usize);
+}
+
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    unsafe {
+        let ptr = miri_alloc(123, 1);
+        *ptr = 42; // Crucially, only a write is printed here, no read!
+        assert_eq!(*ptr, 42);
+        miri_dealloc(ptr, 123, 1);
+    }
+    0
+}
+
+#[panic_handler]
+fn panic_handler(_: &core::panic::PanicInfo) -> ! {
+    loop {}
+}

tests/pass/alloc-access-tracking.stderr

@@ -0,0 +1,37 @@
+note: tracking was triggered
+  --> $DIR/alloc-access-tracking.rs:LL:CC
+   |
+LL |         let ptr = miri_alloc(123, 1);
+   |                   ^^^^^^^^^^^^^^^^^^ created Miri bare-metal heap allocation of 123 bytes (alignment ALIGN bytes) with id 17
+   |
+   = note: BACKTRACE:
+   = note: inside `start` at $DIR/alloc-access-tracking.rs:LL:CC
+
+note: tracking was triggered
+  --> $DIR/alloc-access-tracking.rs:LL:CC
+   |
+LL |         *ptr = 42; // Crucially, only a write is printed here, no read!
+   |         ^^^^^^^^^ write access to allocation with id 17
+   |
+   = note: BACKTRACE:
+   = note: inside `start` at $DIR/alloc-access-tracking.rs:LL:CC
+
+note: tracking was triggered
+  --> $DIR/alloc-access-tracking.rs:LL:CC
+   |
+LL |         assert_eq!(*ptr, 42);
+   |         ^^^^^^^^^^^^^^^^^^^^ read access to allocation with id 17
+   |
+   = note: BACKTRACE:
+   = note: inside `start` at RUSTLIB/core/src/macros/mod.rs:LL:CC
+   = note: this note originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+note: tracking was triggered
+  --> $DIR/alloc-access-tracking.rs:LL:CC
+   |
+LL |         miri_dealloc(ptr, 123, 1);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^ freed allocation with id 17
+   |
+   = note: BACKTRACE:
+   = note: inside `start` at $DIR/alloc-access-tracking.rs:LL:CC
+