llvm-reduce should have a uselistorder reduction

[arsenm]

There should be a uselistorder reduction pass, which tries sorting the uselist for any value with an unsorted uselist. Most of the work is extracting code from the AsmWriter and LLParser into an interface usable from llvm-reduce.

Starter patch: 0001-llvm-reduce-Add-pass-to-reduce-uselistorders.patch

[nikic]

I wish we'd just stop emitting uselistorder in llvm-reduce altogether. It's very rarely actually useful, but breaks reductions for me all the time.

[arsenm]

I wish we'd just stop emitting uselistorder in llvm-reduce altogether. It's very rarely actually useful, but breaks reductions for me all the time.

This would have the net result of removing it most of the time. The reduction uselistorder issue is #58629 and is from recycling the same context between reduction runs and constants having use lists, and you can workaround it by using bitcode input instead of text