[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

lib/ExecutionEngine/RuntimeDyld/JITRegistrar.h

@@ -16,6 +16,7 @@ namespace llvm {
 
 /// Global access point for the JIT debugging interface.
 class JITRegistrar {
+  virtual void anchor();
 public:
   /// Instantiates the JIT service.
   JITRegistrar() {}

lib/ExecutionEngine/RuntimeDyld/ObjectImageCommon.h

@@ -23,6 +23,7 @@ namespace llvm {
 class ObjectImageCommon : public ObjectImage {
   ObjectImageCommon(); // = delete
   ObjectImageCommon(const ObjectImageCommon &other); // = delete
+  virtual void anchor();
 
 protected:
   object::ObjectFile *ObjFile;

lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp

@@ -13,6 +13,7 @@
 
 #define DEBUG_TYPE "dyld"
 #include "llvm/ExecutionEngine/RuntimeDyld.h"
+#include "JITRegistrar.h"
 #include "ObjectImageCommon.h"
 #include "RuntimeDyldELF.h"
 #include "RuntimeDyldImpl.h"
@@ -28,6 +29,11 @@ using namespace llvm::object;
 // Empty out-of-line virtual destructor as the key function.
 RuntimeDyldImpl::~RuntimeDyldImpl() {}
 
+// Pin the JITRegistrar's and ObjectImage*'s vtables to this file.
+void JITRegistrar::anchor() {}
+void ObjectImage::anchor() {}
+void ObjectImageCommon::anchor() {}
+
 namespace llvm {
 
 void RuntimeDyldImpl::registerEHFrames() {