[Interpreter] Do not write Ignition dispatch counters to file by default.

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 281 matching lines @@
 DEFINE_STRING(ignition_filter, "*", "filter for ignition interpreter")
 DEFINE_BOOL(print_bytecode, false,
             "print bytecode generated by ignition interpreter")
 DEFINE_BOOL(trace_ignition, false,
             "trace the bytecodes executed by the ignition interpreter")
 DEFINE_BOOL(trace_ignition_codegen, false,
             "trace the codegen of ignition interpreter bytecode handlers")
 DEFINE_BOOL(trace_ignition_dispatches, false,
             "traces the dispatches to bytecode handlers by the ignition "
             "interpreter")
-DEFINE_STRING(trace_ignition_dispatches_output_file,
-              "v8.ignition_dispatches_table.json",
+DEFINE_STRING(trace_ignition_dispatches_output_file, nullptr,
               "the file to which the bytecode handler dispatch table is "
-              "written")
+              "written (by default, the table is not written to a file)")
 
 // Flags for Crankshaft.
 DEFINE_BOOL(crankshaft, true, "use crankshaft")
 DEFINE_STRING(hydrogen_filter, "*", "optimization filter")
 DEFINE_BOOL(use_gvn, true, "use hydrogen global value numbering")
 DEFINE_INT(gvn_iterations, 3, "maximum number of GVN fix-point iterations")
 DEFINE_BOOL(use_canonicalizing, true, "use hydrogen instruction canonicalizing")
 DEFINE_BOOL(use_inlining, true, "use function inlining")
 DEFINE_BOOL(use_escape_analysis, true, "use hydrogen escape analysis")
 DEFINE_BOOL(use_allocation_folding, true, "use allocation folding")
@@ skipping 854 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