[clang] [HLSL] set alwaysinline on HLSL functions (PR #106588)

[Nico Weber via cfe-commits]

nico wrote:

Looks like the _revert_ broke check-clang: http://45.33.8.238/linux/148045/step_6.txt

Please take a look, and uh, mark that test as UNSUPPORTED if it takes a while to fix, I suppose.

https://github.com/llvm/llvm-project/pull/106588