[DebugInfo][LCSSA] Preserve debug location in lcssa phis

Summary:
When inserting lcssa Phi Nodes in the exit block
mak sure to preserve the original instructions DL.

Reviewers: vsk

Subscribers: JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D50009

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338391 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed