Use signaling NaN for holes in fixed double arrays.

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 907 matching lines @@
   static ExternalReference scheduled_exception_address(Isolate* isolate);
   static ExternalReference address_of_pending_message_obj(Isolate* isolate);
   static ExternalReference address_of_has_pending_message(Isolate* isolate);
   static ExternalReference address_of_pending_message_script(Isolate* isolate);
 
   // Static variables containing common double constants.
   static ExternalReference address_of_min_int();
   static ExternalReference address_of_one_half();
   static ExternalReference address_of_minus_one_half();
   static ExternalReference address_of_negative_infinity();
-  static ExternalReference address_of_canonical_non_hole_nan();
   static ExternalReference address_of_the_hole_nan();
   static ExternalReference address_of_uint32_bias();
 
   static ExternalReference math_log_double_function(Isolate* isolate);
 
   static ExternalReference math_exp_constants(int constant_index);
   static ExternalReference math_exp_log_table();
 
   static ExternalReference page_flags(Page* page);
 
@@ skipping 191 matching lines @@
   NullCallWrapper() { }
   virtual ~NullCallWrapper() { }
   virtual void BeforeCall(int call_size) const { }
   virtual void AfterCall() const { }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_H_