expectedFailure_fast decorator added with minor fixes

theano/gof/destroyhandler.py

@@ -408,9 +408,9 @@ class DestroyHandler(toolbox.Bookkeeper):  # noqa
                     destroy_maps = getattr(app.op, 'destroy_map', {}).values()
                     if idx in [dmap for sublist in destroy_maps for dmap in sublist]:
                         return True
-                    for var in getattr(app.op, 'view_map', {}).keys():
-                        if idx in app.op.view_map[var] and recursive_destroys_finder(app.outputs[var]):
-                                return True
+                    for var_idx in getattr(app.op, 'view_map', {}).keys():
+                        if idx in app.op.view_map[var_idx] and recursive_destroys_finder(app.outputs[var_idx]):
+                            return True
                 return False
 
             for protected_var in protected_list:

theano/tests/unittest_tools.py

@@ -445,3 +445,10 @@ class AttemptManyTimes:
                         current_seed = str(int(current_seed) + 1)
 
         return attempt_multiple_times
+
+
+def expectedFailure_fast():
+    """A Decorator to handle the test cases that are failing when
+    THEANO_FALGS =cycle_detection='fast'.
+    """
+    return unittest.expectedFailure if theano.config.cycle_detection == 'fast' else lambda x: x