Rename Instruction::dropUnknownMetadata() to dropUnknownNonDebugMetadata()
and make it always preserve debug locations, since all callers wanted this
behavior anyway.

This is addressing a post-commit review feedback for r245589.

NFC (inside the LLVM tree).

llvm-svn: 245622
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 310aab4..8c29ed5 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1290,7 +1290,7 @@
 
 void llvm::combineMetadata(Instruction *K, const Instruction *J, ArrayRef<unsigned> KnownIDs) {
   SmallVector<std::pair<unsigned, MDNode *>, 4> Metadata;
-  K->dropUnknownMetadata(KnownIDs);
+  K->dropUnknownNonDebugMetadata(KnownIDs);
   K->getAllMetadataOtherThanDebugLoc(Metadata);
   for (unsigned i = 0, n = Metadata.size(); i < n; ++i) {
     unsigned Kind = Metadata[i].first;