[debugger] fix blacklisted tests.

test/mjsunit/regress/regress-2296.js

Index: test/mjsunit/regress/regress-2296.js
diff --git a/test/mjsunit/regress/regress-2296.js b/test/mjsunit/regress/regress-2296.js
index c00f14f172a0cb099d2ef411fe25bfffbab7e559..b81e8ee78443cba6f4f4277cefb3fa7c2f66a9b9 100644
--- a/test/mjsunit/regress/regress-2296.js
+++ b/test/mjsunit/regress/regress-2296.js
@@ -30,7 +30,11 @@
 Debug = debug.Debug
 
 function listener(event, exec_state, event_data, data) {
-  event_data.script().setSource(1);
+  try {
+    event_data.script().setSource(1);
+  } catch (e) {
+    assertTrue(String(e).indexOf("Source is not a string") > 0);
+  }
 };
 
 Debug.setListener(listener);