[llvm] [TargetLowering][ARM][PowerPC] LHS and RHS should be frozen for 3-way compares (PR #159993)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

Alive doesn't seem to think this is necessary: https://alive2.llvm.org/ce/z/JLx9Rb

https://github.com/llvm/llvm-project/pull/159993