Add support for int-mask and int-mask-of types

[rvanvelzen]

Closes phpstan/phpstan#4732

[rvanvelzen]

I'm not convinced 0 should be part of the union by default, but it's easy enough to add. Psalm does include it, so for parity it might be best to include it.

[ondrejmirtes]

Yeah, let's include 0. It's questionable, in some cases people want 0 and in some cases they don't, but we don't know which is which so let's do the wider and less annoying thing here.

[ondrejmirtes]

One idea for improvement. If the generated integer list is continuous, we could return IntegerRangeType instead.

[ondrejmirtes]

Also please submit documentation for these types to https://phpstan.org/writing-php-code/phpdoc-types - there's a link to edit the page at the bottom.

[ondrejmirtes]

Perfect, thank you!

Two ideas:

1. Test for a scenario when a value that's not power-of-2 (like 3) is part of the values.
2. when a non-integer is mentioned in the PHPDoc, the resulting type should be ErrorType. That will get picked up as unresolvable type by a rule.

[Seldaek]

Great, thanks!