Index: llvm/lib/Bitcode/Reader/MetadataLoader.cpp
===================================================================
--- llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -120,7 +120,6 @@
   struct {
     SmallDenseMap<MDString *, TempMDTuple, 1> Unknown;
     SmallDenseMap<MDString *, DICompositeType *, 1> Final;
-    SmallDenseMap<MDString *, DICompositeType *, 1> FwdDecls;
     SmallVector<std::pair<TrackingMDRef, TempMDTuple>, 1> Arrays;
   } OldTypeRefs;
 
@@ -246,11 +245,6 @@
 
   bool DidReplaceTypeRefs = false;
 
-  // Give up on finding a full definition for any forward decls that remain.
-  for (const auto &Ref : OldTypeRefs.FwdDecls)
-    OldTypeRefs.Final.insert(Ref);
-  OldTypeRefs.FwdDecls.clear();
-
   // Upgrade from old type ref arrays.  In strange cases, this could add to
   // OldTypeRefs.Unknown.
   for (const auto &Array : OldTypeRefs.Arrays) {
@@ -302,10 +296,7 @@
 void BitcodeReaderMetadataList::addTypeRef(MDString &UUID,
                                            DICompositeType &CT) {
   assert(CT.getRawIdentifier() == &UUID && "Mismatched UUID");
-  if (CT.isForwardDecl())
-    OldTypeRefs.FwdDecls.insert(std::make_pair(&UUID, &CT));
-  else
-    OldTypeRefs.Final.insert(std::make_pair(&UUID, &CT));
+  OldTypeRefs.Final.insert(std::make_pair(&UUID, &CT));
 }
 
 Metadata *BitcodeReaderMetadataList::upgradeTypeRef(Metadata *MaybeUUID) {