Introduce JSFunction::EnsureHasInitialMap method.

src/heap.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 606 matching lines @@
   // failed.
   // Please note this does not perform a garbage collection.
   MUST_USE_RESULT MaybeObject* AllocateJSObject(
       JSFunction* constructor,
       PretenureFlag pretenure = NOT_TENURED);
 
   MUST_USE_RESULT MaybeObject* AllocateJSObjectWithAllocationSite(
       JSFunction* constructor,
       Handle<AllocationSite> allocation_site);
 
-  MUST_USE_RESULT MaybeObject* AllocateJSGeneratorObject(
-      JSFunction* function);
-
   MUST_USE_RESULT MaybeObject* AllocateJSModule(Context* context,
                                                 ScopeInfo* scope_info);
 
   // Allocate a JSArray with no elements
   MUST_USE_RESULT MaybeObject* AllocateEmptyJSArray(
       ElementsKind elements_kind,
       PretenureFlag pretenure = NOT_TENURED) {
     return AllocateJSArrayAndStorage(elements_kind, 0, 0,
                                      DONT_INITIALIZE_ARRAY_ELEMENTS,
                                      pretenure);
@@ skipping 2436 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_