tests/dict_fromkeys: Split out skippable part.

tests/basics/dict_fromkeys.py

@@ -7,8 +7,3 @@ d = dict.fromkeys([1, 2, 3, 4], 42)
 l = list(d.values())
 l.sort()
 print(l)
-
-# argument to fromkeys has no __len__
-d = dict.fromkeys(reversed(range(1)))
-#d = dict.fromkeys((x for x in range(1)))
-print(d)

tests/basics/dict_fromkeys2.py

@@ -0,0 +1,11 @@
+try:
+    reversed
+except:
+    import sys
+    print("SKIP")
+    sys.exit()
+
+# argument to fromkeys has no __len__
+d = dict.fromkeys(reversed(range(1)))
+#d = dict.fromkeys((x for x in range(1)))
+print(d)