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 a9398c862da348ac63f20e8e646ec056f5879a77..be47ab4d4975475bf90e5eb7b84a3e810d4a8e49 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 regular JS object and reinitialize.