Reland "[es6] Better support for built-ins subclassing."

src/crankshaft/hydrogen.cc

Index: src/crankshaft/hydrogen.cc
diff --git a/src/crankshaft/hydrogen.cc b/src/crankshaft/hydrogen.cc
index 555291f588efac8062d74813d2be691a32455341..c7e18fec1a352ecd24ecbb35d54bc26883df77f9 100644
--- a/src/crankshaft/hydrogen.cc
+++ b/src/crankshaft/hydrogen.cc
@@ -10132,25 +10132,6 @@ void HOptimizedGraphBuilder::GenerateDataViewInitialize(
 }
 
 
-static Handle<Map> TypedArrayMap(Isolate* isolate,
-                                 ExternalArrayType array_type,
-                                 ElementsKind target_kind) {
-  Handle<Context> native_context = isolate->native_context();
-  Handle<JSFunction> fun;
-  switch (array_type) {
-#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size)                       \
-    case kExternal##Type##Array:                                              \
-      fun = Handle<JSFunction>(native_context->type##_array_fun());           \
-      break;
-
-    TYPED_ARRAYS(TYPED_ARRAY_CASE)
-#undef TYPED_ARRAY_CASE
-  }
-  Handle<Map> map(fun->initial_map());
-  return Map::AsElementsKind(map, target_kind);
-}
-
-
 HValue* HOptimizedGraphBuilder::BuildAllocateExternalElements(
     ExternalArrayType array_type,
     bool is_zero_byte_offset,
@@ -10364,9 +10345,6 @@ void HOptimizedGraphBuilder::GenerateTypedArrayInitialize(
     if (buffer != NULL) {
       elements = BuildAllocateExternalElements(
           array_type, is_zero_byte_offset, buffer, byte_offset, length);
-      Handle<Map> obj_map =
-          TypedArrayMap(isolate(), array_type, fixed_elements_kind);
-      AddStoreMapConstant(obj, obj_map);
     } else {
       DCHECK(is_zero_byte_offset);
       elements = BuildAllocateFixedTypedArray(array_type, element_size,