JET-140 Change function type syntax

and tests for
JET-168 Improve the parser for function and tuple types as receiver types

idea/testData/codegen/classes/extensionClosure.jet

@@ -8,6 +8,6 @@ fun box() : String {
     return if (answer.x == 6 && answer.y == 10) "OK" else "FAIL"
 }
 
-fun apply(arg:Point, f : {Point.(scalar : Int) : Point}) : Point {
+fun apply(arg:Point, f : fun Point.(scalar : Int) : Point) : Point {
     return arg.f(2)
 }