compat.genlib.roundrobin: fix missing imports

dragonmux · whitequark · commit f7c2b9419f9d · 2021-02-04T11:02:27.000Z
diff --git a/nmigen/compat/genlib/roundrobin.py b/nmigen/compat/genlib/roundrobin.py
@@ -1,3 +1,6 @@
+import warnings
+
+from ..fhdl.structure import Signal, If, Case
 from ..._utils import deprecated
 from ..fhdl.module import CompatModule
 
