[clang] [Clang] Add __has_target_builtin macro (PR #126324)

[Yaxun Liu via cfe-commits]

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@@ -357,6 +357,7 @@ void Preprocessor::RegisterBuiltinMacros() {
   Ident__has_builtin = RegisterBuiltinMacro("__has_builtin");
   Ident__has_constexpr_builtin =
       RegisterBuiltinMacro("__has_constexpr_builtin");
+  Ident__has_target_builtin = RegisterBuiltinMacro("__has_target_builtin");
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yxsamliu wrote:

My fear is that some C++ library headers start to use this macro `__has_target_builtin` in place of `__has_builtin`, and we cannot modify such headers.

https://github.com/llvm/llvm-project/pull/126324