A simple test for map compact.

src/flag-definitions.h

 // Copyright 2008 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 183 matching lines @@
             "Flush inline caches prior to mark compact collection.")
 DEFINE_bool(cleanup_caches_in_maps_at_gc, true,
             "Flush code caches in maps during mark compact cycle.")
 
 DEFINE_bool(canonicalize_object_literal_maps, true,
             "Canonicalize maps for object literals.")
 
 DEFINE_bool(use_big_map_space, true,
             "Use big map space, but don't compact if it grew too big.")
 
+DEFINE_int(max_map_space_pages, MapSpace::kMaxMapPageIndex - 1,
+           "Maximum number of pages in map space which still allows to encode "
+           "forwarding pointers.  That's actually a constant, but it's useful "
+           "to control it with a flag for better testing.")
+
 // mksnapshot.cc
 DEFINE_bool(h, false, "print this message")
 DEFINE_bool(new_snapshot, true, "use new snapshot implementation")
 
 // parser.cc
 DEFINE_bool(allow_natives_syntax, false, "allow natives syntax")
 
 // rewriter.cc
 DEFINE_bool(optimize_ast, true, "optimize the ast")
 
@@ skipping 200 matching lines @@
 #undef FLAG
 
 #undef DEFINE_bool
 #undef DEFINE_int
 #undef DEFINE_string
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META