PHP 7.1 compatibility - Implement Nullable types

[asgrim]

I'd like to patch TypeResolver to handle nullable types. Would you prefer a Nullable type with actual type as child, or would you prefer a "flag" to be added to all the types? I think the former is cleaner (and echos how the AST is structured in PhpParser) but just wanted to check what your thoughts were before submitting a patch :) thanks!

[jaapio]

The type itself doesn't have to change for this. A Nullable type to wrap the actual type seems to be the right way to implement this.

Looking forward to your patch 👍

[asgrim]

Excellent thanks - will work on this shortly!