[llvm] Promote pseudo opcodes from 32-bit to 64-bit for instructions that infer extsw elimination in PPCMIPeepholes pass (PR #85451)

[Lei Huang via llvm-commits]

https://github.com/lei137 commented:

Please try to keep your title with 80 chars and do not use hypertext in your PR discription.  

nit: "Summary" is also not needed in the description as that is implied.

https://github.com/llvm/llvm-project/pull/85451