[clang] [compiler-rt] [PGO][Offload] Hide GPU entrypoint on Darwin (PR #132966)

[Ethan Luis McDonough via llvm-commits]

================
@@ -1273,6 +1273,7 @@ COMPILER_RT_VISIBILITY int __llvm_profile_set_file_object(FILE *File,
   return 0;
 }
 
+#ifdef COMPILER_RT_GPU_ENTRYPOINT
----------------
EthanLuisMcDonough wrote:

My reasoning was that it would give us more configuration power if we had a macro that was defined only when we want an entry point. This would give us an easy way to disable the entry point on other platforms if needed. I don't expect that to happen, so I guess we can use `__APPLE__` for now.

https://github.com/llvm/llvm-project/pull/132966