[CIR] Handle __asm labels on function declarations

This updates the CIR direct callee builder code to handle the case of
calls to functions that were declared with an assembly label using `__asm`.
The implementation doesn't actually have any explicit handling of the
AsmLabelAttr. It is handled by the name mangler.

See https://reviews.llvm.org/D137073 and https://reviews.llvm.org/D134362
for details on how this was implemented in classic codegen. The test here
is copied from https://reviews.llvm.org/D134362 because the test in
https://reviews.llvm.org/D134362 requires a target that isn't yet supported
in CIR.

Author: andykaylor

clang/lib/CIR/CodeGen/CIRGenExpr.cpp

@@ -1768,11 +1768,7 @@ CIRGenCallee CIRGenFunction::emitDirectCallee(const GlobalDecl &gd) {
   const auto *fd = cast<FunctionDecl>(gd.getDecl());
 
   if (unsigned builtinID = fd->getBuiltinID()) {
-    if (fd->getAttr<AsmLabelAttr>()) {
-      cgm.errorNYI("AsmLabelAttr");
-    }
-
-    StringRef ident = fd->getName();
+    StringRef ident = cgm.getMangledName(gd);
     std::string fdInlineName = (ident + ".inline").str();
 
     bool isPredefinedLibFunction =

clang/test/CIR/CodeGen/asm-label-inline-builtins.c

@@ -0,0 +1,58 @@
+// RUN: %clang_cc1 -triple x86_64 -fclangir -emit-cir -disable-llvm-passes -o %t-cir.cir %s
+// RUN: FileCheck --input-file=%t-cir.cir %s --check-prefix=CIR
+// RUN: %clang_cc1 -triple x86_64 -fclangir -emit-llvm -disable-llvm-passes -o %t-cir.ll %s
+// RUN: FileCheck --input-file=%t-cir.ll %s --check-prefix=LLVM
+// RUN: %clang_cc1 -triple x86_64 -emit-llvm -disable-llvm-passes -o %t.ll %s
+// RUN: FileCheck --input-file=%t.ll %s --check-prefix=OGCG
+
+
+// Verifies that clang-generated *.inline carry the same name at call and callee
+// site, in spite of asm labels.
+
+typedef struct _IO_FILE FILE;
+extern FILE *stdout;
+extern int vprintf (const char *__restrict __format, __builtin_va_list __arg);
+extern int __vfprintf_chk (FILE *__restrict __stream, int __flag,
+      const char *__restrict __format, __builtin_va_list __ap);
+extern int __vprintf_chk (int __flag, const char *__restrict __format,
+     __builtin_va_list __ap);
+
+extern __typeof (vprintf) vprintf __asm ("__vprintfieee128");
+extern __typeof (__vfprintf_chk) __vfprintf_chk __asm ("__vfprintf_chkieee128");
+extern __typeof (__vprintf_chk) __vprintf_chk __asm ("__vprintf_chkieee128");
+
+extern __inline __attribute__ ((__always_inline__)) __attribute__ ((__gnu_inline__)) __attribute__ ((__artificial__)) int
+vprintf (const char *__restrict __fmt, __builtin_va_list __ap)
+{
+  return __vfprintf_chk (stdout, 2 - 1, __fmt, __ap);
+}
+
+void test(const char *fmt, __builtin_va_list ap) {
+  vprintf(fmt, ap);
+}
+
+// CIR: cir.func internal private @__vprintfieee128.inline({{.*}}) -> !s32i inline(always)
+// CIR:   cir.call @__vfprintf_chkieee128(%{{.*}}, %{{.*}}, %{{.*}}, %{{.*}})
+//
+// CIR: cir.func {{.*}} @test({{.*}})
+// CIR:   cir.call @__vprintfieee128.inline(%{{.*}}, %{{.*}})
+
+
+// LLVM: define internal i32 @__vprintfieee128.inline({{.*}}) #[[ALWAYS_INLINE_ATTR:.*]] {
+// LLVM:   call i32 @__vfprintf_chkieee128(ptr %{{.*}}, i32 1, ptr %{{.*}}, ptr %{{.*}})
+//
+// LLVM: define {{.*}} void @test{{.*}}
+// LLVM:   call i32 @__vprintfieee128.inline(ptr %{{.*}}, ptr %{{.*}})
+//
+// LLVM: attributes #[[ALWAYS_INLINE_ATTR]] = { alwaysinline }
+
+// Note: OGCG emits these in the opposite order, but the content is the same.
+
+
+// OGCG: define {{.*}} void @test{{.*}}
+// OGCG:   call i32 @__vprintfieee128.inline(ptr noundef %{{.*}}, ptr noundef %{{.*}})
+//
+// OGCG: define internal i32 @__vprintfieee128.inline({{.*}}) #[[ALWAYS_INLINE_ATTR:.*]] {
+// OGCG:   call i32 @__vfprintf_chkieee128(ptr noundef %{{.*}}, i32 noundef 1, ptr noundef %{{.*}}, ptr noundef %{{.*}})
+//
+// OGCG: attributes #[[ALWAYS_INLINE_ATTR]] = { alwaysinline {{.*}} }