Cleanup throwing of the RangeError in the runtime to remove duplicated code.

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index 9608f2942820451e4951caf690c0869c8813b213..ae0879d2db9a1c53e4fc06b9d274868c034efe0d 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -6235,6 +6235,11 @@ class Array : public Instance {
   // set to an empty array.
   static RawArray* MakeArray(const GrowableObjectArray& growable_array);
 
+  void CopyFrom(intptr_t dst_start,
+                const Array& source,
+                intptr_t src_start,
+                intptr_t count) const;
+
  protected:
   static RawArray* New(intptr_t class_id,
                        intptr_t len,