[clang] [clang][HIP] Make some math not not work with AMDGCN SPIR-V (PR #128360)

[Alex Voicu via cfe-commits]

AlexVlx wrote:

> This seems to break tests: http://45.33.8.238/linux/161683/step_6.txt
> 
> Please take a look and revert for now if it takes a while to fix.

Should be fixed within the next 30 mins or so, if not I'll revert, apologies for the inconvenience.

https://github.com/llvm/llvm-project/pull/128360