Change the type hierarchy for undefined symbols.

We have to differentiate undefined symbols from bitcode and undefined
symbols from other sources.

Undefined symbols from bitcode should not inhibit the symbol being
internalized. Undefined symbols from other sources should.

llvm-svn: 265536
diff --git a/lld/ELF/OutputSections.cpp b/lld/ELF/OutputSections.cpp
index 6a2e493..18d1ed4 100644
--- a/lld/ELF/OutputSections.cpp
+++ b/lld/ELF/OutputSections.cpp
@@ -1501,7 +1501,7 @@
       return Out<ELFT>::Bss;
     break;
   case SymbolBody::UndefinedElfKind:
-  case SymbolBody::UndefinedKind:
+  case SymbolBody::UndefinedBitcodeKind:
   case SymbolBody::LazyKind:
     break;
   case SymbolBody::DefinedBitcodeKind: