simulation: does not preserve !unambiguous, !semi-deterministic

* spot/twaalgos/simulation.cc: Reset those to maybe.
* tests/core/semidet.test: Add some tests.

tests/core/semidet.test

@@ -79,3 +79,36 @@ cat >expected <<EOF
 X(!p0 W Xp1)
 EOF
 diff out expected
+
+
+# This automaton becomes semi-deterministic once simplified with
+# simulation-based reductions.
+cat >ex <<EOF
+HOA: v1
+AP: 2 "a" "b"
+Start: 0
+States: 6
+Acceptance: 1 Inf(0)
+--BODY--
+State: 0
+[!0] 0
+[0] 1
+[1] 5
+State: 1 {0}
+[0] 1
+State: 2
+[!1] 4
+State: 3
+[1] 4
+State: 4 {0}
+[!0] 4
+State: 5 {0}
+[!1] 5
+[1] 2
+[1] 3
+--END--
+EOF
+
+autfilt -H1.1 ex -v --is-semi-det > out
+autfilt -H1.1 --small out >out2
+autfilt --trust=no -H1.1 --is-semi-det out2