Introduce JSFunction::EnsureHasInitialMap method.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index 2e460487c75468ba5f629a3f8d39ee0684bdcf9e..8737c574b2d1d83e13722bc3d1b614c2f04c88aa 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -4606,15 +4606,7 @@ MaybeObject* Heap::AllocateJSObjectFromMapWithAllocationSite(
 
 MaybeObject* Heap::AllocateJSObject(JSFunction* constructor,
                                     PretenureFlag pretenure) {
-  // Allocate the initial map if absent.
-  if (!constructor->has_initial_map()) {
-    Object* initial_map;
-    { MaybeObject* maybe_initial_map = AllocateInitialMap(constructor);
-      if (!maybe_initial_map->ToObject(&initial_map)) return maybe_initial_map;
-    }
-    constructor->set_initial_map(Map::cast(initial_map));
-    Map::cast(initial_map)->set_constructor(constructor);
-  }
+  ASSERT(constructor->has_initial_map());
   // Allocate the object based on the constructors initial map.
   MaybeObject* result = AllocateJSObjectFromMap(
       constructor->initial_map(), pretenure);
@@ -4629,15 +4621,7 @@ MaybeObject* Heap::AllocateJSObject(JSFunction* constructor,
 
 MaybeObject* Heap::AllocateJSObjectWithAllocationSite(JSFunction* constructor,
     Handle<AllocationSite> allocation_site) {
-  // Allocate the initial map if absent.
-  if (!constructor->has_initial_map()) {
-    Object* initial_map;
-    { MaybeObject* maybe_initial_map = AllocateInitialMap(constructor);
-      if (!maybe_initial_map->ToObject(&initial_map)) return maybe_initial_map;
-    }
-    constructor->set_initial_map(Map::cast(initial_map));
-    Map::cast(initial_map)->set_constructor(constructor);
-  }
+  ASSERT(constructor->has_initial_map());
   // Allocate the object based on the constructors initial map, or the payload
   // advice
   Map* initial_map = constructor->initial_map();
@@ -4669,23 +4653,6 @@ MaybeObject* Heap::AllocateJSObjectWithAllocationSite(JSFunction* constructor,
 }
 
 
-MaybeObject* Heap::AllocateJSGeneratorObject(JSFunction *function) {
-  ASSERT(function->shared()->is_generator());
-  Map *map;
-  if (function->has_initial_map()) {
-    map = function->initial_map();
-  } else {
-    // Allocate the initial map if absent.
-    MaybeObject* maybe_map = AllocateInitialMap(function);
-    if (!maybe_map->To(&map)) return maybe_map;
-    function->set_initial_map(map);
-    map->set_constructor(function);
-  }
-  ASSERT(map->instance_type() == JS_GENERATOR_OBJECT_TYPE);
-  return AllocateJSObjectFromMap(map);
-}
-
-
 MaybeObject* Heap::AllocateJSModule(Context* context, ScopeInfo* scope_info) {
   // Allocate a fresh map. Modules do not have a prototype.
   Map* map;