Implement a `FunctionLike` interface

[roblourens]

See felixfbecker/php-language-server#438 (comment) and isFunctionLike in php-language-server's ParserHelpers.php

[jens1o]

Am I wrong or is this a quite easy task?

I just add a new interface and map them to the points how the parserhelpers recognizes them?

[roblourens]

Yes it would be quite easy.

[jens1o]

I'm going to do this in the next minutes.

[roblourens]

Ok, I started a stopwatch 😁

[jens1o]

Quality before speed 😛