[arm] Turn off the default NaN mode on arm.

src/arm/macro-assembler-arm.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_ARM_MACRO_ASSEMBLER_ARM_H_
 #define V8_ARM_MACRO_ASSEMBLER_ARM_H_
 
 #include "src/assembler.h"
 #include "src/bailout-reason.h"
 #include "src/frames.h"
@@ skipping 471 matching lines @@
             Register dst2,
             const MemOperand& src,
             Condition cond = al);
 
   // Store two consecutive registers to two consecutive memory locations.
   void Strd(Register src1,
             Register src2,
             const MemOperand& dst,
             Condition cond = al);
 
-  // Ensure that FPSCR contains values needed by JavaScript.
-  // We need the NaNModeControlBit to be sure that operations like
-  // vadd and vsub generate the Canonical NaN (if a NaN must be generated).
-  // In VFP3 it will be always the Canonical NaN.
-  // In VFP2 it will be either the Canonical NaN or the negative version
-  // of the Canonical NaN. It doesn't matter if we have two values. The aim
-  // is to be sure to never generate the hole NaN.
-  void VFPEnsureFPSCRState(Register scratch);
-
   // If the value is a NaN, canonicalize the value else, do nothing.
   void VFPCanonicalizeNaN(const DwVfpRegister dst,
                           const DwVfpRegister src,
                           const Condition cond = al);
   void VFPCanonicalizeNaN(const DwVfpRegister value,
                           const Condition cond = al) {
     VFPCanonicalizeNaN(value, value, cond);
   }
 
   // Compare single values and move the result to the normal condition flags.
@@ skipping 1069 matching lines @@
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ARM_MACRO_ASSEMBLER_ARM_H_