Add checks for polymorphic/higher order oracles and higher order entrypoints (AEVM)

test/contracts/complex_types.aes

@@ -50,7 +50,7 @@ contract ComplexTypes =
   entrypoint remote_pair(n : int, s : string) : int * string =
     state.worker.pair(gas = 10000, n, s)
 
-  entrypoint map(f, xs) =
+  function map(f, xs) =
     switch(xs)
       []      => []
       x :: xs => f(x) :: map(f, xs)

test/contracts/test.aes

@@ -91,10 +91,11 @@ contract Identity =
   // }
   // let id(x) = x
   // let main(xs) = map(double,xs)
-  entrypoint z(f,x) = x
+  function z(f,x) = x
   function s(n) = (f,x)=>f(n(f,x))
   function add(m,n) = (f,x)=>m(f,n(f,x))
-  entrypoint main(_) =
+
+  entrypoint main() =
     let three=s(s(s(z)))
     add(three,three)
        (((i)=>i+1),0)

test/contracts/tuple_match.aes

@@ -1,6 +1,6 @@
 contract TuplesMatch =
 
-  entrypoint tuplify3() = (t) => switch(t)
+  function tuplify3() = (t) => switch(t)
     (x, y, z) => 3
 
   entrypoint fst(p : int * string) =