Enable weak embedded maps in optimized code by default.

R=mstarzinger@chromium.org

Review URL: https://chromiumcodereview.appspot.com/12263031

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13666 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/flag-definitions.h

@@ -415,7 +415,7 @@ DEFINE_bool(trace_external_memory, false,
             "it is adjusted.")
 DEFINE_bool(collect_maps, true,
             "garbage collect maps from which no objects can be reached")
-DEFINE_bool(weak_embedded_maps_in_optimized_code, false,
+DEFINE_bool(weak_embedded_maps_in_optimized_code, true,
             "make maps embedded in optimized code weak")
 DEFINE_bool(flush_code, true,
             "flush code that we expect not to use again (during full gc)")