Added first shot at a development shell

src/flag-definitions.h

 // Copyright 2008 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 173 matching lines @@
 DEFINE_string(testing_string_flag, "Hello, world!", "string-flag")
 DEFINE_int(testing_prng_seed, 42, "Seed used for threading test randomness")
 #ifdef WIN32
 DEFINE_string(testing_serialization_file, "C:\\Windows\\Temp\\serdes",
               "file in which to testing_serialize heap")
 #else
 DEFINE_string(testing_serialization_file, "/tmp/serdes",
               "file in which to serialize heap")
 #endif
 
+//
+// Dev shell flags
+//
 
+DEFINE_bool(dump_counters, false, "Dump counters on exit")
 
 //
 // Debug only flags
 //
 #undef FLAG
 #ifdef DEBUG
 #define FLAG FLAG_FULL
 #else
 #define FLAG FLAG_READONLY
 #endif
@@ skipping 90 matching lines @@
 #undef FLAG
 #ifdef ENABLE_DISASSEMBLER
 #define FLAG FLAG_FULL
 #else
 #define FLAG FLAG_READONLY
 #endif
 
 // codegen-ia32.cc / codegen-arm.cc
 DEFINE_bool(print_code, false, "print generated code")
 
-
 // Cleanup...
 #undef FLAG_FULL
 #undef FLAG_READONLY
 #undef FLAG
 
 #undef DEFINE_bool
 #undef DEFINE_int
 #undef DEFINE_string
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META