Revert "Replace HeapNumber as doublebox with an explicit MutableHeapNumber."

src/ia32/macro-assembler-ia32.h

 // 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.
 
 #ifndef V8_IA32_MACRO_ASSEMBLER_IA32_H_
 #define V8_IA32_MACRO_ASSEMBLER_IA32_H_
 
 #include "src/assembler.h"
 #include "src/frames.h"
 #include "src/globals.h"
@@ skipping 620 matching lines @@
   // un-done.
   void UndoAllocationInNewSpace(Register object);
 
   // Allocate a heap number in new space with undefined value. The
   // register scratch2 can be passed as no_reg; the others must be
   // valid registers. Returns tagged pointer in result register, or
   // jumps to gc_required if new space is full.
   void AllocateHeapNumber(Register result,
                           Register scratch1,
                           Register scratch2,
-                          Label* gc_required,
-                          MutableMode mode = IMMUTABLE);
+                          Label* gc_required);
 
   // Allocate a sequential string. All the header fields of the string object
   // are initialized.
   void AllocateTwoByteString(Register result,
                              Register length,
                              Register scratch1,
                              Register scratch2,
                              Register scratch3,
                              Label* gc_required);
   void AllocateAsciiString(Register result,
@@ skipping 455 matching lines @@
   }                                                                       \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_MACRO_ASSEMBLER_IA32_H_