[llvm] Allow Specifying SGMasks for Inline Asm (PR #155491)

[Matt Arsenault via llvm-commits]

arsenm wrote:

To make my position perfectly explicit, I think this should be abandoned. The asm constraints suggested in https://github.com/llvm/llvm-project/pull/157080 should also not be pursued 

https://github.com/llvm/llvm-project/pull/155491