Revert 258157

According the build bots, clang is using the Registry class somewhere as well. Will reapply with appropriate clang changes at a later point.

llvm-svn: 258159

include/llvm/Support/Registry.h

@@ -116,15 +116,14 @@ namespace llvm {
     };
   };
 
-  // Use this macro to stamp out definitions for required static symbols in an
-  // appropriate source file.  This is required to avoid getting multiple
-  // definitions of the Registry's fields in different translation or linkage
-  // units.   
-#define DEFINE_REGISTRY(T)                      \
-  template <>                                    \
-  typename Registry<T>::node *Registry<T>::Head = nullptr; \
-  template <>                          \
-  typename Registry<T>::node *Registry<T>::Tail = nullptr;
+  
+  // Since these are defined in a header file, plugins must be sure to export
+  // these symbols.
+  template <typename T>
+  typename Registry<T>::node *Registry<T>::Head;
+
+  template <typename T>
+  typename Registry<T>::node *Registry<T>::Tail;
 } // end namespace llvm
 
 #endif // LLVM_SUPPORT_REGISTRY_H

lib/CodeGen/GCMetadataPrinter.cpp

@@ -17,7 +17,3 @@ using namespace llvm;
 GCMetadataPrinter::GCMetadataPrinter() {}
 
 GCMetadataPrinter::~GCMetadataPrinter() {}
-
-// Stamp out the registry of GCMetadataPrinter objects so that pulgins can load
-// new Strategies.  
-DEFINE_REGISTRY(GCMetadataPrinter)

lib/CodeGen/GCStrategy.cpp

@@ -20,7 +20,3 @@ GCStrategy::GCStrategy()
     : UseStatepoints(false), NeededSafePoints(0), CustomReadBarriers(false),
       CustomWriteBarriers(false), CustomRoots(false), InitRoots(true),
       UsesMetadata(false) {}
-
-// Stamp out the registry of GCStrategy objects so that pulgins can load new
-// Strategies.  
-DEFINE_REGISTRY(GCStrategy)