Prevent monkey patching

This doesn't affect globals (describe, it, expect, etc). Those belong to
the user and Jasmine doesn't depend on them.

spec/core/TimerSpec.js

@@ -30,4 +30,8 @@ describe('Timer', function() {
       expect(timer.elapsed()).toEqual(jasmine.any(Number));
     });
   });
+
+  isNonMonkeyPatchableClass(jasmineUnderTest.Timer, function() {
+    return new jasmineUnderTest.Timer();
+  });
 });