[clang] [llvm] [AMDGPU] Add alignment attr & propagate alignment through make.buffer.rsrc inst (PR #145278)

[via llvm-commits]

Shoreshen wrote:

> This is still doing the target intrinsic instead of handling ptrmask first? 

Hi @arsenm, I'm going to open a new PR for ptrmask. But since the backward propagate is in the initialization, it may cause some problem (depend on potential constant attr). I'll need to read the code and discuss with shilei on how to solve it~~

https://github.com/llvm/llvm-project/pull/145278