Use mutable heapnumbers to store doubles in fields.

src/arm/stub-cache-arm.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 301 matching lines @@
   __ Move(prototype, Handle<Map>(function->initial_map()));
   // Load the prototype from the initial map.
   __ ldr(prototype, FieldMemOperand(prototype, Map::kPrototypeOffset));
 }
 
 
 void StubCompiler::DoGenerateFastPropertyLoad(MacroAssembler* masm,
                                               Register dst,
                                               Register src,
                                               bool inobject,
-                                              int index) {
+                                              int index,
+                                              StorageType storage_type) {
   int offset = index * kPointerSize;
   if (!inobject) {
     // Calculate the offset into the properties array.
     offset = offset + FixedArray::kHeaderSize;
     __ ldr(dst, FieldMemOperand(src, JSObject::kPropertiesOffset));
     src = dst;
   }
   __ ldr(dst, FieldMemOperand(src, offset));
 }
 
@@ skipping 3377 matching lines @@
     TailCallBuiltin(masm, Builtins::kKeyedStoreIC_Slow);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM