[llvm] [Mips] Fix atomic min/max generate mips4 instructions when compiling for mips2 (PR #159717)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> Delete i16 test and i8 test and delete change in function
> expandAtomicBinOpSubword;

I don't see that change in the original PR? In any case, just deleting the failing tests isn't really a solution to the problem 


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