[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. The memory leaks in this version have been fixed. Thanks
Alexey for pointing them out.

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

Reviewed by Andy

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195064 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCAtom.cpp b/lib/MC/MCAtom.cpp
index d0a64c3..bc353cd 100644
--- a/lib/MC/MCAtom.cpp
+++ b/lib/MC/MCAtom.cpp
@@ -14,6 +14,9 @@
 
 using namespace llvm;
 
+// Pin the vtable to this file.
+void MCAtom::anchor() {}
+
 void MCAtom::remap(uint64_t NewBegin, uint64_t NewEnd) {
   Parent->remap(this, NewBegin, NewEnd);
 }
diff --git a/lib/MC/MCStreamer.cpp b/lib/MC/MCStreamer.cpp
index 2be89e9..2e1d69b 100644
--- a/lib/MC/MCStreamer.cpp
+++ b/lib/MC/MCStreamer.cpp
@@ -22,7 +22,9 @@
 #include <cstdlib>
 using namespace llvm;
 
+// Pin the vtables to this file.
 MCTargetStreamer::~MCTargetStreamer() {}
+void ARMTargetStreamer::anchor() {}
 
 MCStreamer::MCStreamer(MCContext &Ctx, MCTargetStreamer *TargetStreamer)
     : Context(Ctx), TargetStreamer(TargetStreamer), EmitEHFrame(true),
diff --git a/lib/MC/WinCOFFObjectWriter.cpp b/lib/MC/WinCOFFObjectWriter.cpp
index f0f7836..d9ca86d 100644
--- a/lib/MC/WinCOFFObjectWriter.cpp
+++ b/lib/MC/WinCOFFObjectWriter.cpp
@@ -138,7 +138,7 @@
   symbol_map  SymbolMap;
 
   WinCOFFObjectWriter(MCWinCOFFObjectTargetWriter *MOTW, raw_ostream &OS);
-  ~WinCOFFObjectWriter();
+  virtual ~WinCOFFObjectWriter();
 
   COFFSymbol *createSymbol(StringRef Name);
   COFFSymbol *GetOrCreateCOFFSymbol(const MCSymbol * Symbol);
@@ -915,6 +915,9 @@
   Machine(Machine_) {
 }
 
+// Pin the vtable to this file.
+void MCWinCOFFObjectTargetWriter::anchor() {}
+
 //------------------------------------------------------------------------------
 // WinCOFFObjectWriter factory function