Bitcode: Correctly compare a Use against itself

Fix the sort of expected order in the reader to correctly return `false`
when comparing a `Use` against itself.

This was caught by test/Bitcode/binaryIntInstructions.3.2.ll, so I'm
adding a `RUN` line using `llvm-uselistorder` for every test in
`test/Bitcode` that passes.

A few tests still fail, so I'll investigate those next.

This is part of PR5680.