Handle HCheckInstanceType and HIsStringAndBranch in check elimination.

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 b38447b1e7b43235ab279be130d0d372cd46b3a3..9f3b198c6f708f750c6976fe0f986b7bfbeb96b1 100644
--- a/src/hydrogen-check-elimination.h
+++ b/src/hydrogen-check-elimination.h
@@ -16,11 +16,20 @@ namespace internal {
 class HCheckEliminationPhase : public HPhase {
  public:
   explicit HCheckEliminationPhase(HGraph* graph)
-      : HPhase("H_Check Elimination", graph), aliasing_() {
+      : HPhase("H_Check Elimination", graph), aliasing_(),
+        string_maps_(kStringMapsSize, zone()) {
+    // Compute the set of string maps.
+    #define ADD_STRING_MAP(type, size, name, Name)                  \
+      string_maps_.Add(Unique<Map>::CreateImmovable(                \
+              graph->isolate()->factory()->name##_map()), zone());
+    STRING_TYPE_LIST(ADD_STRING_MAP)
+    #undef ADD_STRING_MAP
+    ASSERT_EQ(kStringMapsSize, string_maps_.size());
 #ifdef DEBUG
     redundant_ = 0;
     removed_ = 0;
     removed_cho_ = 0;
+    removed_cit_ = 0;
     narrowed_ = 0;
     loads_ = 0;
     empty_ = 0;
@@ -35,13 +44,20 @@ class HCheckEliminationPhase : public HPhase {
   friend class HCheckTable;
 
  private:
+  const UniqueSet<Map>* string_maps() const { return &string_maps_; }
+
   void PrintStats();
 
   HAliasAnalyzer* aliasing_;
+  #define COUNT(type, size, name, Name) + 1
+  static const int kStringMapsSize = 0 STRING_TYPE_LIST(COUNT);
+  #undef COUNT
+  UniqueSet<Map> string_maps_;
 #ifdef DEBUG
   int redundant_;
   int removed_;
   int removed_cho_;
+  int removed_cit_;
   int narrowed_;
   int loads_;
   int empty_;