Feature request

similar to phpstan/phpstan-src@df27a12

https://phpstan.org/r/ef2f0c50-62c8-480e-bfa6-cbe19dc1199a

more relevant testcases can be inspired from https://github.com/phpstan/phpstan-src/blob/579b075806f32076dfaf55a4f2c913f55ed14a5c/tests/PHPStan/Analyser/data/generic-class-string.php

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