[weak vtables] Remove a bunch of weak vtables

This patch removes most of the trivial cases of weak vtables by pinning them to
a single object file.

Differential Revision: http://llvm-reviews.chandlerc.com/D2068

Reviewed by Andy

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194865 91177308-0d34-0410-b5e6-96231b3b80d8

lib/IR/Metadata.cpp

@@ -65,7 +65,7 @@ class MDNodeOperand : public CallbackVH {
 
 public:
   MDNodeOperand(Value *V) : CallbackVH(V) {}
-  ~MDNodeOperand() {}
+  virtual ~MDNodeOperand();
 
   void set(Value *V) {
     unsigned IsFirst = this->getValPtrInt();
@@ -82,6 +82,8 @@ public:
 };
 } // end namespace llvm.
 
+MDNodeOperand::~MDNodeOperand() {}
+
 
 void MDNodeOperand::deleted() {
   getParent()->replaceOperand(this, 0);