[clang] [clang] [MinGW] Set a predefined __GXX_TYPEINFO_EQUALITY_INLINE=0 for… (PR #96062)

[Fangrui Song via cfe-commits]

================
@@ -926,6 +926,12 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
   if (LangOpts.GNUCVersion && LangOpts.CPlusPlus11)
     Builder.defineMacro("__GXX_EXPERIMENTAL_CXX0X__");
 
+  if (TI.getTriple().isWindowsGNUEnvironment() && LangOpts.CPlusPlus) {
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MaskRay wrote:

The CPlusPlus condition should probably be removed.

```
% x86_64-w64-mingw32-gcc -dM -xc -E /dev/null G TYPEINFO
#define __GXX_TYPEINFO_EQUALITY_INLINE 0
#define __GXX_MERGED_TYPEINFO_NAMES 0
```

https://github.com/llvm/llvm-project/pull/96062