[clang] [llvm] [mlir] [AMDGPU] Add the support for 45-bit buffer resource (PR #159702)

[Shilei Tian via llvm-commits]

shiltian wrote:

> Approved here, though we might want another MLIR reviewer

Feel free to add one if you like.

https://github.com/llvm/llvm-project/pull/159702