[llvm] [AMDGPU] Set hasSideEffects=0 for SALU psuedos (PR #134487)

[Austin Kerbow via llvm-commits]

https://github.com/kerbowa commented:

I'm curious why no side effects is not the default and this needs to be explicit for these pseudos in particular? Is there any motivating test/example where this impacts scheduling or some other optimization?

https://github.com/llvm/llvm-project/pull/134487