Add support for enabling DCHECKs in release mode

src/x64/macro-assembler-x64.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_X64_MACRO_ASSEMBLER_X64_H_
 #define V8_X64_MACRO_ASSEMBLER_X64_H_
 
 #include "src/assembler.h"
 #include "src/bailout-reason.h"
 #include "src/frames.h"
@@ skipping 33 matching lines @@
 
 STATIC_ASSERT(NUMBER_OF_CONSTRAINTS <= 8);
 
 class SmiOperationExecutionMode : public EnumSet<SmiOperationConstraint, byte> {
  public:
   SmiOperationExecutionMode() : EnumSet<SmiOperationConstraint, byte>(0) { }
   explicit SmiOperationExecutionMode(byte bits)
       : EnumSet<SmiOperationConstraint, byte>(bits) { }
 };
 
-#ifdef DEBUG
+#if DCHECK_IS_ON
 bool AreAliased(Register reg1,
                 Register reg2,
                 Register reg3 = no_reg,
                 Register reg4 = no_reg,
                 Register reg5 = no_reg,
                 Register reg6 = no_reg,
                 Register reg7 = no_reg,
                 Register reg8 = no_reg);
 #endif
 
@@ skipping 1587 matching lines @@
     masm->popfq();                                                           \
   }                                                                          \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_MACRO_ASSEMBLER_X64_H_