GreatSyntacticShift: Syntax for function types, function literals, when and tuples

Bug:
fun loop(var times : Int) {
   while(times > 0) {
        val u : (value : Int) -> Unit = { // This arrow is confusing the lookahead
            System.out?.println(it)
        }
        u(times--)
   }
}

compiler/testData/diagnostics/tests/shadowing/ShadowPropertyInClosure.jet

@@ -1,3 +1,3 @@
 val i = 17
 
-val f = { (): Int => var i = 17; i }
+val f = { (): Int -> var i = 17; i }