Fix false positive when type casting in IF statement

[staabm]

closes phpstan/phpstan#11674

see https://3v4l.org/NeugB

[phpstan-bot]

This pull request has been marked as ready for review.

[mvorisek]

reachable for 1 or 01, numeric-string&non-falsy-string?

[staabm]

thank you

[staabm]

we reach ELSE for '0.1' which is a numeric string - https://3v4l.org/NeugB

[mvorisek]

and not for 1.5 - https://3v4l.org/VBPn2 - so string is best or something like string~(''|'0')?

also notice 1x - https://3v4l.org/PGs9f

[staabm]

string~(''|'0') is non-falsy-string. but I think we are in crazy territory land where string should be good enough ;)

[ondrejmirtes]

Took me a while but I found the bad boy for which the elseif can be false: https://3v4l.org/p1sON

[ondrejmirtes]

I think this logic in TypeSpecifier makes more sense. Before the issue we didn't know that we can't compare all the casts to != false. So it makes sense to separate the conditions like this.

We lost precision in a few cases but now it's up to == / != resolution logic in TypeSpecifier to make them more precise again. We don't need to do that now of course.

[ondrejmirtes]

Thank you.

[staabm]

thank you!