[llvm] [MIPS] [MSA] Widen v2i8, v216 and v2i32 vectors (PR #123040)

[Cinhi Young via llvm-commits]

Cyanoxygen wrote:

@wzssyqa I've updated the change and the corresponding test cases based on the previous review comments. Could you please take a look at the new changes.

https://github.com/llvm/llvm-project/pull/123040