Fix test_dis dependency on dict order.

Lib/test/test_dis.py

@@ -268,12 +268,13 @@ Variable names:
    6: args
    7: kwds
 Cell variables:
-   0: e
-   1: d
-   2: f
-   3: y
-   4: x
-   5: z"""
+   0: [edfxyz]
+   1: [edfxyz]
+   2: [edfxyz]
+   3: [edfxyz]
+   4: [edfxyz]
+   5: [edfxyz]"""
+# NOTE: the order of the cell variables above depends on dictionary order!
 
 co_tricky_nested_f = tricky.__func__.__code__.co_consts[1]