Fix in array instance type initialization.

src/hydrogen.cc

 // Copyright 2013 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 8633 matching lines @@
     size_t element_size = 1;  // Bogus initialization.
     Runtime::ArrayIdToTypeAndSize(array_id, &array_type, &element_size);
 
     HInstruction* length = AddUncasted<HDiv>(byte_length,
         Add<HConstant>(static_cast<int32_t>(element_size)));
 
     Add<HStoreNamedField>(obj,
         HObjectAccess::ForJSTypedArrayLength(),
         length);
 
+    Handle<Map> external_array_map(
+        isolate()->heap()->MapForExternalArrayType(array_type));
+
     HValue* elements =
         Add<HAllocate>(
             Add<HConstant>(ExternalArray::kAlignedSize),
             HType::JSArray(),
             NOT_TENURED,
-            static_cast<InstanceType>(FIRST_EXTERNAL_ARRAY_TYPE + array_type));
+            external_array_map->instance_type());
 
-    Handle<Map> external_array_map(
-        isolate()->heap()->MapForExternalArrayType(array_type));
-    Add<HStoreNamedField>(elements,
-        HObjectAccess::ForMap(),
-        Add<HConstant>(external_array_map));
+    AddStoreMapConstant(elements, external_array_map);
 
     HValue* backing_store = Add<HLoadNamedField>(
         buffer, static_cast<HValue*>(NULL),
         HObjectAccess::ForJSArrayBufferBackingStore());
 
     HValue* typed_array_start;
     if (is_zero_byte_offset) {
       typed_array_start = backing_store;
     } else {
       HInstruction* external_pointer =
@@ skipping 2681 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal