Never define 'DEBUG' for non-v8 code

build/standalone.gypi

 # 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 102 matching lines @@
     'configurations': {
       'Debug': {
         'cflags': [ '-g', '-O0' ],
       },
       'Release': {
         # Xcode insists on this empty entry.
       },
     },
     'target_conditions': [
       ['v8_code == 0', {
+        'defines!': [
+          'DEBUG',
+        ],
         'conditions': [
           ['os_posix == 1 and OS != "mac"', {
             'cflags!': [
               '-Werror',
             ],
           }],
           ['OS == "mac"', {
             'xcode_settings': {
               'GCC_TREAT_WARNINGS_AS_ERRORS': 'NO',    # -Werror
             },
           }],
           ['OS == "win"', {
-            'defines!': [
-              'DEBUG',
-            ],
             'msvs_settings': {
               'VCCLCompilerTool': {
                 'WarnAsError': 'false',
               },
             },
           }],
         ],
       }],
     ],
   },
@@ skipping 128 matching lines @@
         },
         'target_conditions': [
           ['_type!="static_library"', {
             'xcode_settings': {'OTHER_LDFLAGS': ['-Wl,-search_paths_first']},
           }],
         ],  # target_conditions
       },  # target_defaults
     }],  # OS=="mac"
   ],
 }