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

[Thurston Dang via cfe-commits]

thurstond wrote:

@nico Sorry, my bad. I didn't notice the test was also updated as a companion to this change (https://github.com/llvm/llvm-project/pull/109023). I'll revert the test as well.

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