[llvm] [Mips] Fix atomic min/max generate mips4 instructions when compiling … (PR #159717)

[Brad Smith via llvm-commits]

brad0 wrote:

> @arsenm #149983 broken atomic-min-max.ll test on the expensive builder. So I revert it and resubmit this PR, could you help review again, thanks!

What changed to fix the issue exposed by the expensive builder?

https://github.com/llvm/llvm-project/pull/159717