[llvm] [NVPTX] Support intrinsics for shared memory special registers (PR #182354)

[Durgadoss R via llvm-commits]

https://github.com/durga4github approved this pull request.

Code changes look good to me except for a few nits.

Let us wait for Alex to have another look before merging.

https://github.com/llvm/llvm-project/pull/182354