Replace HeapNumber as doublebox with an explicit MutableHeapNumber.

src/ia32/stub-cache-ia32.cc

 // Copyright 2012 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 513 matching lines @@
   if (details.type() == CONSTANT) {
     Handle<Object> constant(descriptors->GetValue(descriptor), masm->isolate());
     __ CmpObject(value_reg, constant);
     __ j(not_equal, miss_label);
   } else if (representation.IsSmi()) {
       __ JumpIfNotSmi(value_reg, miss_label);
   } else if (representation.IsHeapObject()) {
     __ JumpIfSmi(value_reg, miss_label);
   } else if (representation.IsDouble()) {
     Label do_store, heap_number;
-    __ AllocateHeapNumber(storage_reg, scratch1, scratch2, slow);
+    __ AllocateHeapNumber(storage_reg, scratch1, scratch2, slow, MUTABLE);
 
     __ JumpIfNotSmi(value_reg, &heap_number);
     __ SmiUntag(value_reg);
     if (CpuFeatures::IsSupported(SSE2)) {
       CpuFeatureScope use_sse2(masm, SSE2);
       __ Cvtsi2sd(xmm0, value_reg);
     } else {
       __ push(value_reg);
       __ fild_s(Operand(esp, 0));
       __ pop(value_reg);
@@ skipping 990 matching lines @@
   // -----------------------------------
   TailCallBuiltin(masm, Builtins::kKeyedLoadIC_Miss);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32