A64: Synchronize with r18581.

src/flag-definitions.h

Index: src/flag-definitions.h
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index 0c7ea439f252f38a96f55bc4cc81d431d3746327..7f59cf0d6045085b417029faa6d6395a0ccd9ccd 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -304,13 +304,11 @@ DEFINE_bool(array_index_dehoisting, true,
 DEFINE_bool(analyze_environment_liveness, true,
             "analyze liveness of environment slots and zap dead values")
 DEFINE_bool(load_elimination, true, "use load elimination")
-DEFINE_bool(check_elimination, false, "use check elimination")
+DEFINE_bool(check_elimination, true, "use check elimination")
 DEFINE_bool(dead_code_elimination, true, "use dead code elimination")
 DEFINE_bool(fold_constants, true, "use constant folding")
 DEFINE_bool(trace_dead_code_elimination, false, "trace dead code elimination")
 DEFINE_bool(unreachable_code_elimination, true, "eliminate unreachable code")
-DEFINE_bool(track_allocation_sites, true,
-            "Use allocation site info to reduce transitions")
 DEFINE_bool(trace_osr, false, "trace on-stack replacement")
 DEFINE_int(stress_runs, 0, "number of stress runs")
 DEFINE_bool(optimize_closures, true, "optimize closures")