[PATCH] D26256: [InstCombine] Don't set debug location when folding through a phi node

[Adrian Prantl via llvm-commits]

aprantl added a comment.

I would still prefer adding an "mergeDebugLoc" API, even if it only returns an empty DebugLoc, so we:

- make it explicit that the debug location is being intentionally dropped and that this code has been audited for correctly updating debug locations (otherwise the code looks no different from a pass that is just not handling debug info at all)
- can improve on it later by, e.g., keeping identical DebugLocs


https://reviews.llvm.org/D26256