Revert r1380 that is breaking frog.

runtime/vm/object.h

Index: runtime/vm/object.h
===================================================================
--- runtime/vm/object.h	(revision 1381)
+++ runtime/vm/object.h	(working copy)
@@ -245,14 +245,6 @@
   static RawClass* GetSingletonClass(int index);
   static const char* GetSingletonClassName(int index);
 
-  static RawClass* CreateAndRegisterCoreInterface(const char* cname,
-                                                  const Script& script,
-                                                  const Library& core_lib);
-  static void RegisterCoreImplClass(const Class& cls,
-                                    const char* cname,
-                                    const Script& impl_script,
-                                    const Library& core_impl_lib);
-
   static void Init(Isolate* isolate);
   static void InitFromSnapshot(Isolate* isolate);
   static void InitOnce();
@@ -749,9 +741,6 @@
   // Check if this type represents the 'List' interface.
   bool IsListInterface() const;
 
-  // Check if this type represents a signature type.
-  bool IsSignatureType() const;
-
   // Check if this type is an interface type.
   bool IsInterfaceType() const {
     if (!HasResolvedTypeClass()) {