[llvm] [CodeGen][NewPM] Extract MachineFunctionProperties modification part to an RAII class (PR #94854)

[Arthur Eubanks via llvm-commits]

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

sorry for the slow review, I've been pretty swamped recently

lg with comment addressed, although I'll probably send out some followup changes at some point to simplify things even more

https://github.com/llvm/llvm-project/pull/94854