Erroneous Offset might not exist

[momala454]

Bug report

phpstan does not know the relation between a variable and another, in certain cases.
In the code snippet, the relation works in hello2 but not in hello

Code snippet that reproduces the problem

https://phpstan.org/r/ff3ed970-82b1-43cb-a427-3851372ded26

Another example where with a relation between $i and $param is not known https://phpstan.org/r/c6bf0d70-3b34-4653-bcb9-726053f24276

Expected output

No error

Did PHPStan help you today? Did it make you happy in any way?

Yes as always

[momala454]

Another example. not sure if I have to create another issue https://phpstan.org/r/c53254dd-ab2c-4323-9be1-184d28881049

[momala454]

Another example. array_search return only existing keys https://phpstan.org/r/702a9f43-f9ad-4915-bba2-252cd8db1540

it looks like reportPossiblyNonexistentGeneralArrayOffset requires a lot of "hacks"

[staabm]

some of these cases will be fixed by phpstan/phpstan-src#3766

[momala454]

@staabm your PR did not seem to have any impact on those

[staabm]

I had another look, but most examples you posted are pretty static analysis unfriendly.

atm I have no idea how these can be improved.