Implement local load/store elimination on basic blocks.

src/flag-definitions.h

Index: src/flag-definitions.h
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index cc153af2542dfca612c4e12c579318931190acbd..7aa40800fbb9d19192a066e42d8354242e90d5fa 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -261,6 +261,7 @@ DEFINE_bool(trace_hydrogen_stubs, false, "trace generated hydrogen for stubs")
 DEFINE_string(trace_hydrogen_file, NULL, "trace hydrogen to given file name")
 DEFINE_string(trace_phase, "HLZ", "trace generated IR for specified phases")
 DEFINE_bool(trace_inlining, false, "trace inlining decisions")
+DEFINE_bool(trace_load_elimination, false, "trace load elimination")
 DEFINE_bool(trace_alloc, false, "trace register allocator")
 DEFINE_bool(trace_all_uses, false, "trace all use positions")
 DEFINE_bool(trace_range, false, "trace range analysis")
@@ -295,6 +296,7 @@ DEFINE_bool(array_index_dehoisting, true,
             "perform array index dehoisting")
 DEFINE_bool(analyze_environment_liveness, true,
             "analyze liveness of environment slots and zap dead values")
+DEFINE_bool(load_elimination, false, "use load 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")