[llvm] [AMDGPU][GlobalISel] Align `selectVOP3PMadMixModsImpl` with the `SelectionDAG` counterpart (PR #110168)

[Shilei Tian via llvm-commits]

================
@@ -0,0 +1,110 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
----------------
shiltian wrote:

Now it is. :-)

https://github.com/llvm/llvm-project/pull/110168