revert r99174. It caused PR6677. Will try to debug why tonight.

llvm-svn: 99188

clang/lib/Sema/SemaDeclCXX.cpp

@@ -5889,7 +5889,7 @@ static bool needsVtable(CXXMethodDecl *MD, ASTContext &Context) {
     break;
 
   case TSK_ExplicitInstantiationDeclaration:
-    return false;
+    return true; //FIXME: This looks wrong.
 
   case TSK_ExplicitInstantiationDefinition:
     // This is method of a explicit instantiation; mark all of the virtual

clang/lib/Sema/SemaTemplate.cpp

@@ -4388,12 +4388,8 @@ Sema::ActOnExplicitInstantiation(Scope *S,
   // Instantiate the members of this class template specialization.
   Def = cast_or_null<ClassTemplateSpecializationDecl>(
                                        Specialization->getDefinition());
-  if (Def) {
-    // Fix a TSK_ExplicitInstantiationDeclaration followed by a
-    // TSK_ExplicitInstantiationDefinition
-    Def->setTemplateSpecializationKind(TSK);
+  if (Def)
     InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK);
-  }
 
   return DeclPtrTy::make(Specialization);
 }