Implement local load/store elimination on basic blocks.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index bf51aa7f3a5aefd9ff345b53eb855563f1265b7e..02f57bedd25287a0848b8a3704a36bbf0a68c4ac 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -43,6 +43,7 @@
 #include "hydrogen-escape-analysis.h"
 #include "hydrogen-infer-representation.h"
 #include "hydrogen-infer-types.h"
+#include "hydrogen-load-elimination.h"
 #include "hydrogen-gvn.h"
 #include "hydrogen-mark-deoptimize.h"
 #include "hydrogen-minus-zero.h"
@@ -2985,6 +2986,8 @@ bool HGraph::Optimize(BailoutReason* bailout_reason) {
 
   if (FLAG_use_escape_analysis) Run<HEscapeAnalysisPhase>();
 
+  if (FLAG_load_elimination) Run<HLoadEliminationPhase>();
+
   CollectPhis();
 
   if (has_osr()) osr()->FinishOsrValues();