[clang] [Clang] Refactor the tests to be more uniform (PR #191944)

[Nick Desaulniers via cfe-commits]

================
@@ -1,292 +1,330 @@
 // RUN: %clang_cc1 -triple i386-unknown-unknown -emit-llvm %s -o - | FileCheck %s
 
-// PR10415
+// PR10415:
+//
+// CHECK:      module asm "foo1"
+// CHECK-NEXT: module asm "foo2"
+// CHECK-NEXT: module asm "foo3"
 __asm__ ("foo1");
 __asm__ ("foo2");
 __asm__ ("foo3");
-// CHECK: module asm "foo1"
-// CHECK-NEXT: module asm "foo2"
-// CHECK-NEXT: module asm "foo3"
 
 void t1(int len) {
-  __asm__ volatile("" : "=&r"(len), "+&r"(len));
+  // CHECK-LABEL: define{{.*}} void @t1
----------------
nickdesaulniers wrote:

Trivial aside, it looks like `rg CHECK-LABEL clang/test/` shows that `CHECK-LABEL` supports either this style, or just `@t1`.  IDK if it makes it more readable, but consider omitting the `define{{.*}} <return type>` from the checks, since that's really not what we're testing here.

Example:
```suggestion
  // CHECK-LABEL: @t1
```

https://github.com/llvm/llvm-project/pull/191944