fix callcombo

[horasal]

Test code:

foo: class{
    v : Int
    isOdd :Bool {
        get { v % 2 == 1 }
    }

    isEven ::= v %2 == 0

    init: func

    test: func -> Func(Int) {
        return func(a: Int){ a toString() println()}
    }
}

bar := foo new()

a := bar test()
a(1)

bar test()(1)

bar test()(1) can not be correctly recognized in this case.
Parser may break callcombo into two function call bar test() and null ().

This commit fix this problem.

Another testcase:(should throw error that can not call on void function instead of crash)

//!shouldfail

foo: class{
    v : Int
    isOdd :Bool {
        get { v % 2 == 1 }
    }

    isEven ::= v %2 == 0

    init: func

    test: func {}
}

bar := foo new()

bar test()()