[clang] [HIP] Don't add -fvisibility=hidden for SPIR-V compilation flow (PR #184821)

[Joseph Huber via cfe-commits]

jhuber6 wrote:

Then the backend should be fixed, we shouldn't just disable things to hide when they're broken. This would still crash if the user passed `-fvisibility=hidden` and visibility is an LLVM-IR feature. If you need a quick work-around you can just pass `-fvisibility=protected`.

https://github.com/llvm/llvm-project/pull/184821