Flag optimize-constructed-arrays turned on.

This routes array construction through a hydrogen stub, and enables use of
allocation site info tracking.

BUG=

Review URL: https://codereview.chromium.org/14616010

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14490 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/flag-definitions.h

@@ -252,7 +252,7 @@ DEFINE_bool(unreachable_code_elimination, false,
             "eliminate unreachable code (hidden behind soft deopts)")
 DEFINE_bool(track_allocation_sites, true,
             "Use allocation site info to reduce transitions")
-DEFINE_bool(optimize_constructed_arrays, false,
+DEFINE_bool(optimize_constructed_arrays, true,
             "Use allocation site info on constructed arrays")
 DEFINE_bool(trace_osr, false, "trace on-stack replacement")
 DEFINE_int(stress_runs, 0, "number of stress runs")

test/mjsunit/allocation-site-info.js

@@ -41,7 +41,7 @@
 
 // support_smi_only_arrays = %HasFastSmiElements(new Array(1,2,3,4,5,6,7,8));
 support_smi_only_arrays = true;
-optimize_constructed_arrays = false;
+optimize_constructed_arrays = true;
 
 if (support_smi_only_arrays) {
   print("Tests include smi-only arrays.");