[llvm] Reland [AMDGPU] Support block load/store for CSR #130013 (PR #137169)

[Shilei Tian via llvm-commits]

https://github.com/shiltian approved this pull request.

Given it is a reland, no complaint as long as it can pass tests.

https://github.com/llvm/llvm-project/pull/137169