Retain class_exists expression types in closure

[staabm]

analog #1929

class_exists() is special, because there's no way to unload a class in PHP, so it should "survive" when entering closure.

[VincentLanglet]

Shouldnt be the same with trait exist and unterface exist and enum exists ?

[VincentLanglet]

Might be more place to check ?

• MutatingScope::rememberConstructorExpressions: Check class_exists and function_exists but not other _exists function

• MutatingScope::isInClassExists: Check class_exists, enum_exists, interface_exists ; seems ok according to the name of method at first sight but looking at ClassExistsFunctionTypeSpecifyingExtension we should maybe add enum_exists to be similar.

[staabm]

Might be more place to check ?

* MutatingScope::rememberConstructorExpressions: Check class_exists and function_exists but not other `_exists` function

agree - but I think these are problems for a separate PR

* MutatingScope::isInClassExists: Check class_exists, enum_exists, interface_exists ; seems ok according to the name of method at first sight but looking at `ClassExistsFunctionTypeSpecifyingExtension` we should maybe add enum_exists to be similar.

yeah need to be explored separately

[VincentLanglet]

Did you check this new error @staabm ? https://github.com/phpstan/phpstan-src/actions/runs/26359187340/job/77591608540?pr=5746

Edit: Seems like related to https://github.com/briannesbitt/Carbon/blob/0b004790c36cd389cc64dd928434fb17d477fe2b/src/Carbon/Lang/sr_Latn_BA.php#L17

[staabm]

• MutatingScope::rememberConstructorExpressions: Check class_exists and function_exists but not other _exists function

looked into it. I don't see a use-case yet, which would be improved when we remember also e.g. interface_exists, trait_exists or similar.

*_exist already implies class_exists, which means e.g. https://phpstan.org/r/46861d03-af49-45e5-b4ab-26d6a595c928 works as expected

[staabm]

• MutatingScope::isInClassExists: Check class_exists, enum_exists, interface_exists ; seems ok according to the name of method at first sight but looking at ClassExistsFunctionTypeSpecifyingExtension
  we should maybe add enum_exists to be similar.

#5751