[clang] [Clang][OpenCL][AMDGPU] OpenCL Kernel stubs should be assigned alwaysinline attribute (PR #137769)

[Matt Arsenault via cfe-commits]

arsenm wrote:

Apparently the inliner has an arbitrary size threshold even for single uses. I don't see the point of that, we should probably remove that 

https://github.com/llvm/llvm-project/pull/137769