[llvm] [Mips] Fix clang crashes when compiling a variadic function while targeting mips3 (PR #130558)

[Fangrui Song via llvm-commits]

MaskRay wrote:

The title was truncated due to github. It's more readable to ignore github and fix the title.

> Because mips3 has the feature 'FeatureGP64

It seems to apply to newer processors as well.

https://github.com/llvm/llvm-project/pull/130558