Put preservation of optimized code map behind a flag.

src/flag-definitions.h

 // Copyright 2012 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 250 matching lines @@
 DEFINE_bool(optimize_constructed_arrays, true,
             "Use allocation site info on constructed arrays")
 DEFINE_bool(trace_osr, false, "trace on-stack replacement")
 DEFINE_int(stress_runs, 0, "number of stress runs")
 DEFINE_bool(optimize_closures, true, "optimize closures")
 DEFINE_bool(lookup_sample_by_shared, true,
             "when picking a function to optimize, watch for shared function "
             "info, not JSFunction itself")
 DEFINE_bool(cache_optimized_code, true,
             "cache optimized code for closures")
+DEFINE_bool(flush_optimized_code_cache, true,
+            "flushes the cache of optimized code for closures on every GC")
 DEFINE_bool(inline_construct, true, "inline constructor calls")
 DEFINE_bool(inline_arguments, true, "inline functions with arguments object")
 DEFINE_bool(inline_accessors, true, "inline JavaScript accessors")
 DEFINE_int(loop_weight, 1, "loop weight for representation inference")
 
 DEFINE_bool(optimize_for_in, true,
             "optimize functions containing for-in loops")
 DEFINE_bool(opt_safe_uint32_operations, true,
             "allow uint32 values on optimize frames if they are used only in "
             "safe operations")
@@ skipping 504 matching lines @@
 #undef DEFINE_bool
 #undef DEFINE_int
 #undef DEFINE_string
 #undef DEFINE_implication
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META
 #undef FLAG_MODE_DEFINE_IMPLICATIONS