[heap] Preserve optimized code maps accross GCs.

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 362 matching lines @@
 DEFINE_BOOL(store_elimination, false, "use store elimination")
 DEFINE_BOOL(dead_code_elimination, true, "use dead code elimination")
 DEFINE_BOOL(fold_constants, true, "use constant folding")
 DEFINE_BOOL(trace_dead_code_elimination, false, "trace dead code elimination")
 DEFINE_BOOL(unreachable_code_elimination, true, "eliminate unreachable code")
 DEFINE_BOOL(trace_osr, false, "trace on-stack replacement")
 DEFINE_INT(stress_runs, 0, "number of stress runs")
 DEFINE_BOOL(lookup_sample_by_shared, true,
             "when picking a function to optimize, watch for shared function "
             "info, not JSFunction itself")
-DEFINE_BOOL(flush_optimized_code_cache, true,
+DEFINE_BOOL(flush_optimized_code_cache, false,
             "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(escape_analysis_iterations, 2,
            "maximum number of escape analysis fix-point iterations")
 
 DEFINE_BOOL(optimize_for_in, true, "optimize functions containing for-in loops")
 
 DEFINE_BOOL(concurrent_recompilation, true,
@@ skipping 725 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