Fix representation issue in FastArrayPushStub

test/mjsunit/regress/regress-599089-array-push.js

Index: test/mjsunit/regress/regress-599089-array-push.js
diff --git a/test/message/regress/regress-4829-1.js b/test/mjsunit/regress/regress-599089-array-push.js
similarity index 56%
copy from test/message/regress/regress-4829-1.js
copy to test/mjsunit/regress/regress-599089-array-push.js
index 1ad5feda8cb96cd24e4c47f7407c9699d150c327..9049a4b8b669451730f5fb54487ddbaa6bb749ca 100644
--- a/test/message/regress/regress-4829-1.js
+++ b/test/mjsunit/regress/regress-599089-array-push.js
@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-function tag() {}
 
-tag(tag`\xyy`);
+var array = [1.2, 1.2];
+array.length = 0;
+array.push(undefined);
+assertEquals(1, array.length);
+assertEquals([undefined], array);