Elide hole checks on KeyedLoads of holey double arrays.

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index a95424a1c9e455ffa4a9664770844aee75b28b7d..a0d9bbc1b6e80ebee98fa8049d4e521b669904c6 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -389,6 +389,14 @@ class HGraph: public ZoneObject {
     return is_recursive_;
   }
 
+  void MarkDependsOnEmptyArrayProtoElements() {
+    depends_on_empty_array_proto_elements_ = true;
+  }
+
+  bool depends_on_empty_array_proto_elements() {
+    return depends_on_empty_array_proto_elements_;
+  }
+
   void RecordUint32Instruction(HInstruction* instr) {
     if (uint32_instructions_ == NULL) {
       uint32_instructions_ = new(zone()) ZoneList<HInstruction*>(4, zone());
@@ -449,6 +457,7 @@ class HGraph: public ZoneObject {
   bool is_recursive_;
   bool use_optimistic_licm_;
   bool has_soft_deoptimize_;
+  bool depends_on_empty_array_proto_elements_;
   int type_change_checksum_;
 
   DISALLOW_COPY_AND_ASSIGN(HGraph);
@@ -1002,6 +1011,7 @@ class HGraphBuilder {
       HValue* dependency,
       ElementsKind elements_kind,
       bool is_store,
+      LoadKeyedHoleMode load_mode,
       KeyedAccessStoreMode store_mode);
 
   HValue* BuildCheckForCapacityGrow(HValue* object,
@@ -1024,6 +1034,7 @@ class HGraphBuilder {
       bool is_js_array,
       ElementsKind elements_kind,
       bool is_store,
+      LoadKeyedHoleMode load_mode,
       KeyedAccessStoreMode store_mode,
       Representation checked_index_representation = Representation::None());