Move hash code from hidden string to a private symbol

src/mips64/macro-assembler-mips64.cc

 // 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.
 
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_MIPS64
 
@@ skipping 510 matching lines @@
 
   // hash = hash * 2057;
   sll(scratch, reg0, 11);
   sll(at, reg0, 3);
   addu(reg0, reg0, at);
   addu(reg0, reg0, scratch);
 
   // hash = hash ^ (hash >> 16);
   srl(at, reg0, 16);
   xor_(reg0, reg0, at);
+  And(reg0, reg0, Operand(0x3fffffff));
 }
 
 
 void MacroAssembler::LoadFromNumberDictionary(Label* miss,
                                               Register elements,
                                               Register key,
                                               Register result,
                                               Register reg0,
                                               Register reg1,
                                               Register reg2) {
@@ skipping 5653 matching lines @@
   }
   if (mag.shift > 0) sra(result, result, mag.shift);
   srl(at, dividend, 31);
   Addu(result, result, Operand(at));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS64