[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/MC/WinCOFFObjectWriter.cpp

@@ -138,7 +138,7 @@ public:
   symbol_map  SymbolMap;
 
   WinCOFFObjectWriter(MCWinCOFFObjectTargetWriter *MOTW, raw_ostream &OS);
-  ~WinCOFFObjectWriter();
+  virtual ~WinCOFFObjectWriter();
 
   COFFSymbol *createSymbol(StringRef Name);
   COFFSymbol *GetOrCreateCOFFSymbol(const MCSymbol * Symbol);
@@ -898,6 +898,9 @@ MCWinCOFFObjectTargetWriter::MCWinCOFFObjectTargetWriter(unsigned Machine_) :
   Machine(Machine_) {
 }
 
+// pin vtable to this file
+void MCWinCOFFObjectTargetWriter::anchor() {}
+
 //------------------------------------------------------------------------------
 // WinCOFFObjectWriter factory function