Add missing test

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/tests/kernel/normalizer.cpp

@@ -233,7 +233,7 @@ static void tst5() {
 #endif
 }
 
-void tst6() {
+static void tst6() {
     environment env;
     expr x = Const("x");
     expr t = Fun({x, Type()}, mk_app(x, x));
@@ -253,5 +253,6 @@ int main() {
     tst3();
     tst4();
     tst5();
+    tst6();
     return has_violations() ? 1 : 0;
 }

tests/lean/tst8.lean

@@ -8,3 +8,6 @@ Definition f (A: Type) (a : A) : A :=
    let b := g A a,
        c := g A b
    in c
+
+Show f _ 10.
+Show f _ (- 10).

tests/lean/tst8.lean.expected.out

@@ -3,3 +3,5 @@
 Π (A : Type) (a : A), A
   Assumed: g
   Defined: f
+f Nat 10
+f Int (- 10)