Basic support for tracking smi-only arrays on ia32.

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index 422f7e7b447ed37a26e77c0469073da7e07a74d9..819c1a63f74a81e8639577e19b0ee55819d53faa 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -203,7 +203,9 @@ class Factory {
   Handle<JSGlobalPropertyCell> NewJSGlobalPropertyCell(
       Handle<Object> value);
 
-  Handle<Map> NewMap(InstanceType type, int instance_size);
+  Handle<Map> NewMap(InstanceType type,
+                     int instance_size,
+                     ElementsKind elements_kind = FAST_ELEMENTS);
 
   Handle<JSObject> NewFunctionPrototype(Handle<JSFunction> function);
 
@@ -253,6 +255,10 @@ class Factory {
       Handle<FixedArray> elements,
       PretenureFlag pretenure = NOT_TENURED);
 
+  void SetContent(Handle<JSArray> array, Handle<FixedArray> elements);
+
+  void EnsureCanContainNonSmiElements(Handle<JSArray> array);
+
   Handle<JSProxy> NewJSProxy(Handle<Object> handler, Handle<Object> prototype);
 
   // Change the type of the argument into a JS object/function and reinitialize.