[DebugInfo][2/N] Instruction referencing tests: cope with switched variable order

[jmorse]

Summary

Enabling instruction referencing causes a few variable locations to switch order -- i.e., they switch position in the output DWARF, or sometimes the order of DBG_VALUEs. This isn't significant from a correctness point of view, but does lead to some tests needing updating. The largest change is debug-loclists.ll, where a large amount of location-list offset information changes -- correctly I believe, but it could do with closer examination.