[llvm] [lit] Refactor available `ptxas` features (PR #154439)

[Justin Fargnoli via llvm-commits]

justinfargnoli wrote:

@vvereschaka I put up #155912 as a fix forward the issue. However, if that doesn't work for whatever reason, I also opened #155914 to revert the change. 

https://github.com/llvm/llvm-project/pull/154439