BUG Probleme grave de scheduling, cf [ff].

test/good/sampling_stateful_output2.ept

@@ -0,0 +1,20 @@
+node f(x:int) returns (y:int)
+var z :int;
+let
+  z = 3;
+  y = 0 fby z;
+tel
+
+node ff(x:int; c:bool) returns (y:int)
+var z :int;
+let
+  z = 3;
+  y = (0 fby z) when c;
+tel
+
+node fff(x:int; c:bool) returns ()
+var z :int; y:int;
+let
+  z = 3;
+  y = (0 fby z) when c;
+tel