Debugger: require debugger to be active when dealing with breaks.

test/mjsunit/regress/regress-2318.js

Index: test/mjsunit/regress/regress-2318.js
diff --git a/test/mjsunit/regress/regress-2318.js b/test/mjsunit/regress/regress-2318.js
index e31e0f904e032a0744e50d4f8b4efba53fd513c7..771d195212e34cdea7aefc24df7c5802049f99ad 100644
--- a/test/mjsunit/regress/regress-2318.js
+++ b/test/mjsunit/regress/regress-2318.js
@@ -56,11 +56,12 @@ function f() {
 };
 
 Debug = debug.Debug;
-var bp = Debug.setBreakPoint(f, 0);
 
 function listener(event, exec_state, event_data, data) {
   result = exec_state.frame().evaluate("i").value();
 };
 
 Debug.setListener(listener);
+var bp = Debug.setBreakPoint(f, 0);
+
 assertThrows(function() { f(); }, RangeError);