Add flag to tracing element kind transitions

src/flag-definitions.h

 // Copyright 2011 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 509 matching lines @@
 //
 // Disassembler only flags
 //
 #undef FLAG
 #ifdef ENABLE_DISASSEMBLER
 #define FLAG FLAG_FULL
 #else
 #define FLAG FLAG_READONLY
 #endif
 
+// elements.cc
+DEFINE_bool(trace_elements_transitions, false, "trace elements transitions")
+
 // code-stubs.cc
 DEFINE_bool(print_code_stubs, false, "print code stubs")
 
 // codegen-ia32.cc / codegen-arm.cc
 DEFINE_bool(print_code, false, "print generated code")
 DEFINE_bool(print_opt_code, false, "print optimized code")
 DEFINE_bool(print_unopt_code, false, "print unoptimized code before "
             "printing optimized code based on it")
 DEFINE_bool(print_code_verbose, false, "print more information for code")
 DEFINE_bool(print_builtin_code, false, "print generated code for builtins")
 
 // 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