minor bugfixes

migen/fhdl/structure.py

@@ -432,7 +432,7 @@ class _Assign(_Statement):
 
 
 def _check_statement(s):
-    if isinstance(s, Iterable):
+    if isinstance(s, _collections.Iterable):
         return all(_check_statement(ss) for ss in s)
     else:
         return isinstance(s, _Statement)

migen/sim.py

@@ -80,7 +80,7 @@ class Evaluator:
             try:
                 return self.signal_values[node]
             except KeyError:
-                return node.reset
+                return node.reset.value
         elif isinstance(node, _Operator):
             operands = [self.eval(o) for o in node.operands]
             if node.op == "-":