[debugger] add utility to print break location.

src/flag-definitions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file defines all of the flags.  It is separated into different section,
 // for Debug, Release, Logging and Profiling, etc.  To add a new flag, find the
 // correct section, and use one of the DEFINE_ macros, without a trailing ';'.
 //
 // This include does not have a guard, because it is a template-style include,
 // which can be included multiple times in different modes.  It expects to have
@@ skipping 973 matching lines @@
 DEFINE_BOOL(trace_isolates, false, "trace isolate state changes")
 
 // Regexp
 DEFINE_BOOL(regexp_possessive_quantifier, false,
             "enable possessive quantifier syntax for testing")
 DEFINE_BOOL(trace_regexp_bytecodes, false, "trace regexp bytecode execution")
 DEFINE_BOOL(trace_regexp_assembler, false,
             "trace regexp macro assembler calls.")
 DEFINE_BOOL(trace_regexp_parser, false, "trace regexp parsing")
 
+// Debugger
+DEFINE_BOOL(print_break_location, false, "print source location on debug break")
+
 //
 // Logging and profiling flags
 //
 #undef FLAG
 #define FLAG FLAG_FULL
 
 // log.cc
 DEFINE_BOOL(log, false,
             "Minimal logging (no API, code, GC, suspect, or handles samples).")
 DEFINE_BOOL(log_all, false, "Log all events to the log file.")
@@ skipping 159 matching lines @@
 #undef DEFINE_ALIAS_FLOAT
 #undef DEFINE_ALIAS_ARGS
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META
 #undef FLAG_MODE_DEFINE_IMPLICATIONS
 
 #undef COMMA