Support lazy creating

[arakov]

To support lazy allocation support .! operator. So we could simplify the following code:

List<TapeFunction> a := nil;

//while (...) {
// ...
    if (a == nil)
        a := new List<TapeFunction>();

    a.append(...)
// }

with

//while (...) {
// ...
    a.!append(...)
// }

[arakov]

The code looks like this:

A
{
    foo()
    {
        console.writeLine("bar")
    }
}

public program()
{
    A a;

    a.!foo(); // checking if the variable is nil, and creating if required
}