[Debugify] Support checking Machine IR debug info

Authored by xiangzhangllvm on Dec 14 2020, 11:48 PM.


[Debugify] Support checking Machine IR debug info
Add mir-check-debug pass to check MIR-level debug info.

For IR-level, currently, LLVM have debugify + check-debugify to generate
and check debug IR. Much like the IR-level pass debugify, mir-debugify
inserts sequentially increasing line locations to each MachineInstr in a
Module, But there is no equivalent MIR-level check-debugify pass, So now
we support it at "mir-check-debug".

Reviewed By: djtodoro

Differential Revision: https://reviews.llvm.org/D91595