Never hchange nan-hole to hole or hole to nan-hole.

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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 4611 matching lines @@
     XMMRegister input_reg = ToDoubleRegister(instr->value());
     __ ucomisd(input_reg, input_reg);
     __ j(parity_odd, &no_special_nan_handling);
     __ subq(rsp, Immediate(kDoubleSize));
     __ movsd(MemOperand(rsp, 0), input_reg);
     __ cmpl(MemOperand(rsp, sizeof(kHoleNanLower32)),
             Immediate(kHoleNanUpper32));
     Label canonicalize;
     __ j(not_equal, &canonicalize);
     __ addq(rsp, Immediate(kDoubleSize));
-    __ Move(reg, factory()->the_hole_value());
+    __ Move(reg, factory()->undefined_value());
     __ jmp(&done);
     __ bind(&canonicalize);
     __ addq(rsp, Immediate(kDoubleSize));
     __ Set(kScratchRegister, BitCast<uint64_t>(
         FixedDoubleArray::canonical_not_the_hole_nan_as_double()));
     __ movq(input_reg, kScratchRegister);
   }
 
   __ bind(&no_special_nan_handling);
   DeferredNumberTagD* deferred = new(zone()) DeferredNumberTagD(this, instr);
@@ skipping 974 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64