[lto] Make sure that ctors are added to the combined module.

Summary:
More generally, appending linkage is a special case that we don't want
to create a SymbolBody for.

Reviewers: rafael, ruiu

Subscribers: Bigcheese, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18012

llvm-svn: 263179

lld/ELF/InputFiles.cpp

@@ -450,8 +450,10 @@ void BitcodeFile::parse(DenseSet<StringRef> &ComdatGroups) {
         continue;
     if (!(Flags & BasicSymbolRef::SF_Global))
         continue;
-    if (Flags & BasicSymbolRef::SF_FormatSpecific)
+    if (GV->hasAppendingLinkage()) {
+      ExtraKeeps.push_back(GV->getName().copy(Alloc));
       continue;
+    }
     uint8_t Visibility = getGvVisibility(GV);
 
     SmallString<64> Name;