[runtime] Store constructor function index on primitive maps.

src/ia32/builtins-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_IA32
 
 #include "src/code-factory.h"
 #include "src/codegen.h"
@@ skipping 206 matching lines @@
       __ mov(edx, factory->undefined_value());
       __ lea(ecx, Operand(ebx, JSObject::kHeaderSize));
       if (!is_api_function) {
         Label no_inobject_slack_tracking;
 
         // Check if slack tracking is enabled.
         __ cmp(esi, Map::kSlackTrackingCounterEnd);
         __ j(less, &no_inobject_slack_tracking);
 
         // Allocate object with a slack.
-        __ movzx_b(esi, FieldOperand(eax, Map::kInObjectPropertiesOffset));
+        __ movzx_b(
+            esi,
+            FieldOperand(
+                eax, Map::kInObjectPropertiesOrConstructorFunctionIndexOffset));
         __ movzx_b(eax, FieldOperand(eax, Map::kUnusedPropertyFieldsOffset));
         __ sub(esi, eax);
         __ lea(esi,
                Operand(ebx, esi, times_pointer_size, JSObject::kHeaderSize));
         // esi: offset of first field after pre-allocated fields
         if (FLAG_debug_code) {
           __ cmp(esi, edi);
           __ Assert(less_equal,
                     kUnexpectedNumberOfPreAllocatedPropertyFields);
         }
@@ skipping 1524 matching lines @@
 
   __ bind(&ok);
   __ ret(0);
 }
 
 #undef __
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_IA32