Elide hole checks on KeyedLoads of holey double arrays.

src/contexts.h

Index: src/contexts.h
diff --git a/src/contexts.h b/src/contexts.h
index 434b274147e1920fad6314d38e133c94476aabcf..6e241f171fdb5c7b76eb6fac5394356d38cefcc7 100644
--- a/src/contexts.h
+++ b/src/contexts.h
@@ -112,6 +112,7 @@ enum BindingFlags {
   V(JSON_OBJECT_INDEX, JSObject, json_object) \
   V(REGEXP_FUNCTION_INDEX, JSFunction, regexp_function) \
   V(INITIAL_OBJECT_PROTOTYPE_INDEX, JSObject, initial_object_prototype) \
+  V(INITIAL_ARRAY_PROTOTYPE_INDEX, JSObject, initial_array_prototype) \
   V(CREATE_DATE_FUN_INDEX, JSFunction,  create_date_fun) \
   V(TO_NUMBER_FUN_INDEX, JSFunction, to_number_fun) \
   V(TO_STRING_FUN_INDEX, JSFunction, to_string_fun) \
@@ -263,6 +264,7 @@ class Context: public FixedArray {
     FUNCTION_INSTANCE_MAP_INDEX,
     STRICT_MODE_FUNCTION_INSTANCE_MAP_INDEX,
     INITIAL_OBJECT_PROTOTYPE_INDEX,
+    INITIAL_ARRAY_PROTOTYPE_INDEX,
     BOOLEAN_FUNCTION_INDEX,
     NUMBER_FUNCTION_INDEX,
     STRING_FUNCTION_INDEX,
@@ -434,6 +436,10 @@ class Context: public FixedArray {
     ASSERT(IsNativeContext());                            \
     set(index, value);                                    \
   }                                                       \
+  bool is_##name(type* value) {                           \
+    ASSERT(IsNativeContext());                            \
+    return type::cast(get(index)) == value;               \
+  }                                                       \
   type* name() {                                          \
     ASSERT(IsNativeContext());                            \
     return type::cast(get(index));                        \