Bug report

PHPStan 0.12.10

Test for array type before using array_shift() function doesn't work if result of test is stored into variable.

Code snippet that reproduces the problem

https://phpstan.org/r/77b64d46-6237-41d5-bf76-0dff0b17ad08

Expected output

All three variants written in code snippet are same but they have not same result.