Ensure that we do not accidentally emit debug code.

src/x64/macro-assembler-x64.h

 // Copyright 2012 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 942 matching lines @@
 
   template<typename Field>
   void DecodeField(Register reg) {
     static const int shift = Field::kShift + kSmiShift;
     static const int mask = Field::kMask >> Field::kShift;
     shr(reg, Immediate(shift));
     and_(reg, Immediate(mask));
     shl(reg, Immediate(kSmiShift));
   }
 
-  // Abort execution if argument is not a number. Used in debug code.
-  void AbortIfNotNumber(Register object);
+  // Abort execution if argument is not a number, enabled via --debug-code.
+  void AssertNumber(Register object);
 
-  // Abort execution if argument is a smi. Used in debug code.
-  void AbortIfSmi(Register object);
+  // Abort execution if argument is a smi, enabled via --debug-code.
+  void AssertNotSmi(Register object);
 
-  // Abort execution if argument is not a smi. Used in debug code.
-  void AbortIfNotSmi(Register object);
-  void AbortIfNotSmi(const Operand& object);
+  // Abort execution if argument is not a smi, enabled via --debug-code.
+  void AssertSmi(Register object);
+  void AssertSmi(const Operand& object);
 
   // Abort execution if a 64 bit register containing a 32 bit payload does not
-  // have zeros in the top 32 bits.
-  void AbortIfNotZeroExtended(Register reg);
+  // have zeros in the top 32 bits, enabled via --debug-code.
+  void AssertZeroExtended(Register reg);
 
-  // Abort execution if argument is a string. Used in debug code.
-  void AbortIfNotString(Register object);
+  // Abort execution if argument is not a string, enabled via --debug-code.
+  void AssertString(Register object);
 
-  // Abort execution if argument is not the root value with the given index.
-  void AbortIfNotRootValue(Register src,
-                           Heap::RootListIndex root_value_index,
-                           const char* message);
+  // Abort execution if argument is not the root value with the given index,
+  // enabled via --debug-code.
+  void AssertRootValue(Register src,
+                       Heap::RootListIndex root_value_index,
+                       const char* message);
 
   // ---------------------------------------------------------------------------
   // Exception handling
 
   // Push a new try handler and link it into try handler chain.
   void PushTryHandler(StackHandler::Kind kind, int handler_index);
 
   // Unlink the stack handler on top of the stack from the try handler chain.
   void PopTryHandler();
 
@@ skipping 502 matching lines @@
     masm->popfd();                                                        \
   }                                                                       \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_MACRO_ASSEMBLER_X64_H_