[runtime] Store constructor function index on primitive maps.

src/arm/builtins-arm.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_ARM
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
@@ skipping 424 matching lines @@
         Label no_inobject_slack_tracking;
 
         // Check if slack tracking is enabled.
         __ ldr(ip, FieldMemOperand(r2, Map::kBitField3Offset));
         __ DecodeField<Map::Counter>(ip);
         __ cmp(ip, Operand(Map::kSlackTrackingCounterEnd));
         __ b(lt, &no_inobject_slack_tracking);
 
         // Allocate object with a slack.
         __ ldr(r0, FieldMemOperand(r2, Map::kInstanceSizesOffset));
-        __ Ubfx(r0, r0, Map::kInObjectPropertiesByte * kBitsPerByte,
+        __ Ubfx(r0, r0, Map::kInObjectPropertiesOrConstructorFunctionIndexByte *
+                            kBitsPerByte,
                 kBitsPerByte);
         __ ldr(r2, FieldMemOperand(r2, Map::kInstanceAttributesOffset));
         __ Ubfx(r2, r2, Map::kUnusedPropertyFieldsByte * kBitsPerByte,
                 kBitsPerByte);
         __ sub(r0, r0, Operand(r2));
         __ add(r0, r5, Operand(r0, LSL, kPointerSizeLog2));
         // r0: offset of first field after pre-allocated fields
         if (FLAG_debug_code) {
           __ add(ip, r4, Operand(r3, LSL, kPointerSizeLog2));  // End of object.
           __ cmp(r0, ip);
@@ skipping 1409 matching lines @@
   }
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM