Implement global check elimination using the HFlowEngine.

src/hydrogen-check-elimination.h

Index: src/hydrogen-check-elimination.h
diff --git a/src/hydrogen-check-elimination.h b/src/hydrogen-check-elimination.h
index fa01964f6faf091c3f2504b6d2cfe416e0a09b16..f38e6152fb139a31321b0d99c73bc6b108ecb65b 100644
--- a/src/hydrogen-check-elimination.h
+++ b/src/hydrogen-check-elimination.h
@@ -29,6 +29,7 @@
 #define V8_HYDROGEN_CHECK_ELIMINATION_H_
 
 #include "hydrogen.h"
+#include "hydrogen-alias-analysis.h"
 
 namespace v8 {
 namespace internal {
@@ -38,12 +39,33 @@ namespace internal {
 class HCheckEliminationPhase : public HPhase {
  public:
   explicit HCheckEliminationPhase(HGraph* graph)
-      : HPhase("H_Check Elimination", graph) { }
+    : HPhase("H_Check Elimination", graph),
+      aliasing_(),
+      redundant_(0),
+      removed_(0),
+      narrowed_(0),
+      loads_(0),
+      empty_(0),
+      compares_true_(0),
+      compares_false_(0),
+      transitions_(0) { }
 
   void Run();
 
+  friend class HCheckTable;
+
  private:
-  void EliminateLocalChecks(HBasicBlock* block);
+  void PrintStats();
+
+  HAliasAnalyzer* aliasing_;
+  int redundant_;
+  int removed_;
+  int narrowed_;
+  int loads_;
+  int empty_;
+  int compares_true_;
+  int compares_false_;
+  int transitions_;
 };