Fix slow enum-union with lots of cases

[staabm]

closes phpstan/phpstan#10772

this effectively reverts 0a39b42 but fixes a nasty perf problem

the reproducer of #10772 took >2 minutes before this change and finishes instantly after it

$ time ../phpstan-src/bin/phpstan analyse --debug
Note: Using configuration file C:\dvl\Workspace\stan-long\phpstan.neon.
C:\dvl\Workspace\stan-long\src\test.php


 [OK] No errors



real    0m2.669s
user    0m0.000s
sys     0m0.000s

Todo: regression test

[staabm]

Todo: regression test

not sure where to put the regression test, since we need a composer.json/lock. in the past we used AnalyzerIntegration test, but this doesn't have composer.json project level.

should I do a end-2-end test? if so, how/where to put a "timeout" for it?

---

alternatively I can try to reduce the existing test to something without external composer dependencies

[staabm]

(added regression test)

[VincentLanglet]

If the issue is with getEnumCases be slow.

Shouldn't be introduced a new method isSomething, implemented by all types in order to avoid the error message

Doing instanceof PHPStan\\\\Type\\\\Enum\\\\EnumCaseObjectType is error\\-prone and deprecated\\

?

Then

if ($types[$i]->isSomething()->yes()) {

[staabm]

Not sure its worth a new type-method just for this bottleneck

[ondrejmirtes]

Thank you!