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/UnusedVariables.jet

@@ -1,4 +1,4 @@
-namespace unused_variables
+package unused_variables
 
 fun testSimpleCases() {
     var i = <!VARIABLE_WITH_REDUNDANT_INITIALIZER!>2<!>
@@ -103,11 +103,11 @@ fun testInnerFunctions() {
 
 fun testFunctionLiterals() {
     var x = 1
-    var <!UNUSED_VARIABLE!>fl<!> = { (): Int =>
+    var <!UNUSED_VARIABLE!>fl<!> = { (): Int ->
         x
     }
     var y = 2
-    var <!UNUSED_VARIABLE!>fl1<!> = { (): Unit =>
+    var <!UNUSED_VARIABLE!>fl1<!> = { (): Unit ->
         doSmth(y)
     }
 }