[libclc] [libclc] Update default triple support for AMD and deprecate 32-bit PTX (PR #174415)

[Joseph Huber via cfe-commits]

jhuber6 wrote:

For your downstream use, I already fixed the COV flag and https://github.com/llvm/llvm-project/pull/174454 should fix the `wchar` issue. I don't know why you need the last hack around the `-mcpu` options. Do you know how `libclc` handles ISA specific code? It seems to just do aliases.

https://github.com/llvm/llvm-project/pull/174415