[idea] easy chaining calls

[iperov]

easy chaining without introducing SelfType, Generic mess, or boilerplating.

Instead of a dot ., we only need another character (for example ->) that replaces the return type of the next function with a reference to the same class

Example

public class Foo
{
    private int value;

    public int Set(int input)
    {
        value = input;
        return value;
    }
}

Foo foo = new Foo();
foo.Set(1).Set(2); // error

Foo foo = new Foo()->Set(1)
                   ->Set(2); // ok

int val = foo->Set(3).Set(4); // ok

[huoyaoyuan]

#7325 and #902 #311 #252 #7231 #169 etc

we only need another character (for example ->)

-> can't be used because it conflicts with pointer-returning method.

[iperov]

the issues shown are selftype and generic mess.
-> is an example, not a direct statement of the need to choose this particular symbol.