[turbofan] extend escape analysis to reduce CheckMaps

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 481 matching lines @@
 DEFINE_BOOL(turbo_loop_variable, true, "Turbofan loop variable optimization")
 DEFINE_BOOL(turbo_cf_optimization, true, "optimize control flow in TurboFan")
 DEFINE_BOOL(turbo_frame_elision, true, "elide frames in TurboFan")
 DEFINE_BOOL(turbo_escape, true, "enable escape analysis")
 DEFINE_BOOL(turbo_instruction_scheduling, false,
             "enable instruction scheduling in TurboFan")
 DEFINE_BOOL(turbo_stress_instruction_scheduling, false,
             "randomly schedule instructions to stress dependency tracking")
 DEFINE_BOOL(turbo_store_elimination, true,
             "enable store-store elimination in TurboFan")
+DEFINE_BOOL(turbo_experimental, false,
+            "enable crashing features, for testing purposes only")
 // TODO(turbofan): Rename --crankshaft to --optimize eventually.
 DEFINE_IMPLICATION(turbo, crankshaft)
 
 // Flags to help platform porters
 DEFINE_BOOL(minimal, false,
             "simplifies execution model to make porting "
             "easier (e.g. always use Ignition, never use Crankshaft")
 DEFINE_IMPLICATION(minimal, ignition)
 DEFINE_NEG_IMPLICATION(minimal, crankshaft)
 DEFINE_NEG_IMPLICATION(minimal, use_ic)
@@ skipping 788 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