[PGO][Offload] Don't define GPU entrypoint on Darwin#132966

EthanLuisMcDonough merged 3 commits intollvm:mainllvm/llvm-project:mainfrom

EthanLuisMcDonough:gpupgo_hide_darwinEthanLuisMcDonough/llvm-project:gpupgo_hide_darwinCopy head branch name to clipboard