[clang] [llvm] [mlir] [AMDGPU] Generalize global.load.lds to buffer fat pointers (PR #134911)

[Krzysztof Drewniak via cfe-commits]

krzysz00 wrote:

That is to say, because the offset you're gathering from is on the buffer fat pointer, the addrspace(7) version of this load has the same function signature as `global.load.lds`, not `buffer.raw.ptr.load.lds`

https://github.com/llvm/llvm-project/pull/134911