[IRObjectFile] Try to be defensive, add a break.

Suggested by Sean Silva.

llvm-svn: 273519

llvm/lib/Object/IRObjectFile.cpp

@@ -119,6 +119,7 @@ void IRObjectFile::CollectAsmUndefinedRefs(
     case RecordStreamer::GlobalWeak:
       Res |= BasicSymbolRef::SF_Weak;
       Res |= BasicSymbolRef::SF_Global;
+      break;
     }
     AsmUndefinedRefs(Key, BasicSymbolRef::Flags(Res));
   }