[llvm] [Triple] Make mipsel-*-windows-* use COFF files by default (PR #107809)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

> Ping. The commit has been approved by reviewer @mstorsjo. What is the next step?

The next steps would be for me or someone else to press the merge button.

I think this change in itself is fine, but I was kind of hoping to see more followup from others on the discussion at https://github.com/llvm/llvm-project/pull/107744#issuecomment-2339376671.

https://github.com/llvm/llvm-project/pull/107809