[clang] [Clang][AMDGPU] Add builtins for instrinsic `llvm.amdgcn.raw.buffer.store` (PR #94576)

[Jay Foad via cfe-commits]

jayfoad wrote:

Is there really a good use case for this? Can you use regular stores to addrspace(7) instead? @krzysz00

Also, do you really need a separate builtin for every legal type, or is there some way they can be type-overloaded?

https://github.com/llvm/llvm-project/pull/94576