Add input check to %DebugSetScriptSource.

test/mjsunit/regress/regress-2296.js

Index: test/mjsunit/regress/regress-2296.js
diff --git a/test/mjsunit/regress/regress-iteration-order.js b/test/mjsunit/regress/regress-2296.js
similarity index 88%
copy from test/mjsunit/regress/regress-iteration-order.js
copy to test/mjsunit/regress/regress-2296.js
index 76f5c3ffcaf5d71ea5a579425e477c2607a90e1c..c00f14f172a0cb099d2ef411fe25bfffbab7e559 100644
--- a/test/mjsunit/regress/regress-iteration-order.js
+++ b/test/mjsunit/regress/regress-2296.js
@@ -25,18 +25,16 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-var x = {a: 1, b: 2, c: 3};
+// Flags: --expose-debug-as debug
 
-x.__proto__ = {};
+Debug = debug.Debug
 
-delete x.b;
+function listener(event, exec_state, event_data, data) {
+  event_data.script().setSource(1);
+};
 
-x.d = 4;
+Debug.setListener(listener);
 
-s = "";
+eval('0');
 
-for (key in x) {
-    s += x[key];
-}
-
-assertEquals("134", s);
+Debug.setListener(null);