Implement KeyedStoreICs to grow arrays on out-of-bound stores.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index bc18bf8fabde108e6acfbbfa49e2d5fe878beb0c..ef22af87178265704d961337f6dafc0af2d16034 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -168,6 +168,11 @@ enum CompareMapMode {
   ALLOW_ELEMENT_TRANSITION_MAPS
 };
 
+enum KeyedAccessGrowMode {
+  DO_NOT_ALLOW_JSARRAY_GROWTH,
+  ALLOW_JSARRAY_GROWTH
+};
+
 const int kElementsKindCount = LAST_ELEMENTS_KIND - FIRST_ELEMENTS_KIND + 1;
 
 void PrintElementsKind(FILE* out, ElementsKind kind);
@@ -4216,6 +4221,28 @@ class Code: public HeapObject {
   // Find the first map in an IC stub.
   Map* FindFirstMap();
 
+  class ExtraICStateStrictMode: public BitField<StrictModeFlag, 0, 1> {};
+  class ExtraICStateKeyedAccessGrowMode:
+      public BitField<KeyedAccessGrowMode, 1, 1> {};  // NOLINT
+
+  static const int kExtraICStateGrowModeShift = 1;
+
+  static inline StrictModeFlag GetStrictMode(ExtraICState extra_ic_state) {
+    return ExtraICStateStrictMode::decode(extra_ic_state);
+  }
+
+  static inline KeyedAccessGrowMode GetKeyedAccessGrowMode(
+      ExtraICState extra_ic_state) {
+    return ExtraICStateKeyedAccessGrowMode::decode(extra_ic_state);
+  }
+
+  static inline ExtraICState ComputeExtraICState(
+      KeyedAccessGrowMode grow_mode,
+      StrictModeFlag strict_mode) {
+    return ExtraICStateKeyedAccessGrowMode::encode(grow_mode) |
+        ExtraICStateStrictMode::encode(strict_mode);
+  }
+
   // Flags operations.
   static inline Flags ComputeFlags(
       Kind kind,