Index: include/clang/AST/DeclTemplate.h
===================================================================
--- include/clang/AST/DeclTemplate.h
+++ include/clang/AST/DeclTemplate.h
@@ -800,6 +800,8 @@
     return SpecIterator<EntryType>(isEnd ? Specs.end() : Specs.begin());
   }
 
+  void loadLazySpecializationsImpl() const;
+
   template <class EntryType> typename SpecEntryTraits<EntryType>::DeclType*
   findSpecializationImpl(llvm::FoldingSetVector<EntryType> &Specs,
                          ArrayRef<TemplateArgument> Args, void *&InsertPos);
@@ -818,6 +820,13 @@
     /// was explicitly specialized.
     llvm::PointerIntPair<RedeclarableTemplateDecl*, 1, bool>
       InstantiatedFromMember;
+
+    /// \brief If non-null, points to an array of specializations (including
+    /// partial specializations) known only by their external declaration IDs.
+    ///
+    /// The first value in the array is the number of specializations/partial
+    /// specializations that follow.
+    uint32_t *LazySpecializations = nullptr;
   };
 
   /// \brief Pointer to the common data shared by all declarations of this
@@ -985,13 +994,6 @@
     /// require the use of this information.
     TemplateArgument *InjectedArgs = nullptr;
 
-    /// \brief If non-null, points to an array of specializations known only
-    /// by their external declaration IDs.
-    ///
-    /// The first value in the array is the number of of specializations
-    /// that follow.
-    uint32_t *LazySpecializations = nullptr;
-
     Common() = default;
   };
 
@@ -2075,13 +2077,6 @@
     /// \brief The injected-class-name type for this class template.
     QualType InjectedClassNameType;
 
-    /// \brief If non-null, points to an array of specializations (including
-    /// partial specializations) known only by their external declaration IDs.
-    ///
-    /// The first value in the array is the number of of specializations/
-    /// partial specializations that follow.
-    uint32_t *LazySpecializations = nullptr;
-
     Common() = default;
   };
 
@@ -2895,13 +2890,6 @@
     llvm::FoldingSetVector<VarTemplatePartialSpecializationDecl>
     PartialSpecializations;
 
-    /// \brief If non-null, points to an array of specializations (including
-    /// partial specializations) known ownly by their external declaration IDs.
-    ///
-    /// The first value in the array is the number of of specializations/
-    /// partial specializations that follow.
-    uint32_t *LazySpecializations = nullptr;
-
     Common() = default;
   };
 
Index: lib/AST/DeclTemplate.cpp
===================================================================
--- lib/AST/DeclTemplate.cpp
+++ lib/AST/DeclTemplate.cpp
@@ -182,6 +182,21 @@
   return Common;
 }
 
+void RedeclarableTemplateDecl::loadLazySpecializationsImpl() const {
+  // Grab the most recent declaration to ensure we've loaded any lazy
+  // redeclarations of this template.
+  //
+  // FIXME: Avoid walking the entire redeclaration chain here.
+  CommonBase *CommonBasePtr = getMostRecentDecl()->getCommonPtr();
+  if (CommonBasePtr->LazySpecializations) {
+    ASTContext &Context = getASTContext();
+    uint32_t *Specs = CommonBasePtr->LazySpecializations;
+    CommonBasePtr->LazySpecializations = nullptr;
+    for (uint32_t I = 0, N = *Specs++; I != N; ++I)
+      (void)Context.getExternalSource()->GetExternalDecl(Specs[I]);
+  }
+}
+
 template<class EntryType>
 typename RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::DeclType *
 RedeclarableTemplateDecl::findSpecializationImpl(
@@ -190,7 +205,7 @@
   using SETraits = SpecEntryTraits<EntryType>;
 
   llvm::FoldingSetNodeID ID;
-  EntryType::Profile(ID,Args, getASTContext());
+  EntryType::Profile(ID, Args, getASTContext());
   EntryType *Entry = Specs.FindNodeOrInsertPos(ID, InsertPos);
   return Entry ? SETraits::getDecl(Entry)->getMostRecentDecl() : nullptr;
 }
@@ -251,18 +266,7 @@
 }
 
 void FunctionTemplateDecl::LoadLazySpecializations() const {
-  // Grab the most recent declaration to ensure we've loaded any lazy
-  // redeclarations of this template.
-  //
-  // FIXME: Avoid walking the entire redeclaration chain here.
-  Common *CommonPtr = getMostRecentDecl()->getCommonPtr();
-  if (CommonPtr->LazySpecializations) {
-    ASTContext &Context = getASTContext();
-    uint32_t *Specs = CommonPtr->LazySpecializations;
-    CommonPtr->LazySpecializations = nullptr;
-    for (uint32_t I = 0, N = *Specs++; I != N; ++I)
-      (void)Context.getExternalSource()->GetExternalDecl(Specs[I]);
-  }
+  loadLazySpecializationsImpl();
 }
 
 llvm::FoldingSetVector<FunctionTemplateSpecializationInfo> &
@@ -330,18 +334,7 @@
 }
 
 void ClassTemplateDecl::LoadLazySpecializations() const {
-  // Grab the most recent declaration to ensure we've loaded any lazy
-  // redeclarations of this template.
-  //
-  // FIXME: Avoid walking the entire redeclaration chain here.
-  Common *CommonPtr = getMostRecentDecl()->getCommonPtr();
-  if (CommonPtr->LazySpecializations) {
-    ASTContext &Context = getASTContext();
-    uint32_t *Specs = CommonPtr->LazySpecializations;
-    CommonPtr->LazySpecializations = nullptr;
-    for (uint32_t I = 0, N = *Specs++; I != N; ++I)
-      (void)Context.getExternalSource()->GetExternalDecl(Specs[I]);
-  }
+  loadLazySpecializationsImpl();
 }
 
 llvm::FoldingSetVector<ClassTemplateSpecializationDecl> &
@@ -941,21 +934,8 @@
                                      DeclarationName(), nullptr, nullptr);
 }
 
-// TODO: Unify across class, function and variable templates?
-//       May require moving this and Common to RedeclarableTemplateDecl.
 void VarTemplateDecl::LoadLazySpecializations() const {
-  // Grab the most recent declaration to ensure we've loaded any lazy
-  // redeclarations of this template.
-  //
-  // FIXME: Avoid walking the entire redeclaration chain here.
-  Common *CommonPtr = getMostRecentDecl()->getCommonPtr();
-  if (CommonPtr->LazySpecializations) {
-    ASTContext &Context = getASTContext();
-    uint32_t *Specs = CommonPtr->LazySpecializations;
-    CommonPtr->LazySpecializations = nullptr;
-    for (uint32_t I = 0, N = *Specs++; I != N; ++I)
-      (void)Context.getExternalSource()->GetExternalDecl(Specs[I]);
-  }
+  loadLazySpecializationsImpl();
 }
 
 llvm::FoldingSetVector<VarTemplateSpecializationDecl> &