[compiler-rt] [llvm] [JITLink][Mips] Add ELF backend (PR #224578)

[Lang Hames via llvm-commits]

https://github.com/lhames commented:

Looks great @FlyGoat!

Just a heads up that work is progressing on the new ORC runtime (`llvm-project/orc-rt`). I think your work in this commit will port over naturally, but in the future we expect to add new features that may require more mips-specific code. Do you want me to ping you if/when that happens?

https://github.com/llvm/llvm-project/pull/224578