Added regression test

[staabm]

closes phpstan/phpstan#13310

[phpstan-bot]

This pull request has been marked as ready for review.

[ondrejmirtes]

Have you checked that this is slow on 2.1.18? Thanks.

[ondrejmirtes]

I guess this has also been slower after your "unset" PR and faster again after 56a30c2

[staabm]

this PR:

➜  phpstan-src git:(b13310) hyperfine 'php vendor/bin/phpunit tests/PHPStan/Analyser/AnalyserIntegrationTest.php --filter testBug13310'
Benchmark 1: php vendor/bin/phpunit tests/PHPStan/Analyser/AnalyserIntegrationTest.php --filter testBug13310
  Time (mean ± σ):      1.373 s ±  0.017 s    [User: 1.212 s, System: 0.153 s]
  Range (min … max):    1.348 s …  1.407 s    10 runs

this PR with 56a30c2 reverted

• I had to cancel the process after 60 seconds

[ondrejmirtes]

Thank you!