[clang] [Clang][AMDGPU] Add __builtin_amdgcn_s_buffer_load_<T> (PR #203352)

[Krzysztof Drewniak via cfe-commits]

krzysz00 wrote:

I'm going to note I'm working on a patch to add a `ptr addrspace(8)`-based s.buffer.load intrinsic that I think will work better applied on top of this

https://github.com/llvm/llvm-project/pull/203352