[llvm] Partial revert "[NVPTX] Enhance mul.wide and mad.wide peepholes#150477" (PR #155024)

[Justin Fargnoli via llvm-commits]

justinfargnoli wrote:

> I am curious whether you could make any sense of why it became slower?

To be frank, I'm not sure. I didn't dig deep into the SASS diff. I'd guess that some `ptxas` peephole isn't being triggered. 

https://github.com/llvm/llvm-project/pull/155024