Fix some usage of "this" in builtins

src/macros.py

 # Copyright 2006-2009 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 74 matching lines @@
 macro IS_FUNCTION(arg)          = (%_IsFunction(arg));
 macro IS_REGEXP(arg)            = (%_ClassOf(arg) === 'RegExp');
 macro IS_DATE(arg)              = (%_ClassOf(arg) === 'Date');
 macro IS_NUMBER_WRAPPER(arg)    = (%_ClassOf(arg) === 'Number');
 macro IS_STRING_WRAPPER(arg)    = (%_ClassOf(arg) === 'String');
 macro IS_BOOLEAN_WRAPPER(arg)   = (%_ClassOf(arg) === 'Boolean');
 macro IS_ERROR(arg)             = (%_ClassOf(arg) === 'Error');
 macro IS_SCRIPT(arg)            = (%_ClassOf(arg) === 'Script');
 macro IS_ARGUMENTS(arg)         = (%_ClassOf(arg) === 'Arguments');
 macro IS_GLOBAL(arg)            = (%_ClassOf(arg) === 'global');
+macro IS_UNDETECTABLE(arg)      = (%_IsUndetectableObject(arg));
 macro FLOOR(arg)                = $floor(arg);
 
 # Inline macros. Use %IS_VAR to make sure arg is evaluated only once.
 macro NUMBER_IS_NAN(arg) = (!%_IsSmi(%IS_VAR(arg)) && !(arg == arg));
 macro TO_INTEGER(arg)    = (%_IsSmi(%IS_VAR(arg)) ? arg : ToInteger(arg));
 macro TO_INT32(arg)      = (%_IsSmi(%IS_VAR(arg)) ? arg : (arg >> 0));
 macro TO_UINT32(arg)     = (arg >>> 0);
 
 # Macros implemented in Python.
 python macro CHAR_CODE(str) = ord(str[1]);
@@ skipping 23 matching lines @@
 macro MS_FROM_TIME(time) = (Modulo(time, 1000));
 
 # Last input and last subject of regexp matches.
 macro LAST_SUBJECT(array) = ((array)[1]);
 macro LAST_INPUT(array) = ((array)[2]);
 
 # REGEXP_FIRST_CAPTURE
 macro CAPTURE(index) = (3 + (index));
 const CAPTURE0 = 3;
 const CAPTURE1 = 4;