[clang] [lld] [llvm] [clang][MIPS] Add support for mipsel-windows-* targets (PR #107744)

[Martin Storsjö via cfe-commits]

mstorsjo wrote:

> For the Mips backend itself, I would ask the Mips backend code maintainer... but we don't have a maintainer for Mips. And we don't have any buildbots. I'm really not sure about adding complexity to a backend which is already suffering from a lack of anyone that has any experience with it. (People familiar with other backends can sort of step in to review changes to Mips, but it's hard to do a good review for anything non-trivial.)

FWIW, I've seen @wzssyqa do some amount of work around MIPS, should we ask them about whether want to take up the role as MIPS backend maintainer?

https://github.com/llvm/llvm-project/pull/107744