Reland "Enable loads and stores to global vars through property cell shortcuts installed into paren…

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 647 matching lines @@
             "Dump heap object allocations/movements/size_updates")
 
 
 // v8.cc
 DEFINE_BOOL(use_idle_notification, true,
             "Use idle notification to reduce memory footprint.")
 // ic.cc
 DEFINE_BOOL(use_ic, true, "use inline caching")
 DEFINE_BOOL(trace_ic, false, "trace inline cache state transitions")
 DEFINE_BOOL(vector_stores, false, "use vectors for store ics")
-DEFINE_BOOL(global_var_shortcuts, false, "use ic-less global loads and stores")
+DEFINE_BOOL(global_var_shortcuts, true, "use ic-less global loads and stores")
 
 // macro-assembler-ia32.cc
 DEFINE_BOOL(native_code_counters, false,
             "generate extra code for manipulating stats counters")
 
 // mark-compact.cc
 DEFINE_BOOL(always_compact, false, "Perform compaction on every full GC")
 DEFINE_BOOL(never_compact, false,
             "Never perform compaction on full GC - testing only")
 DEFINE_BOOL(compact_code_space, true, "Compact code space on full collections")
@@ skipping 384 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