Give class template context to conditional checker

[KmeCnin]

This PR fixes bug reported here: phpstan/phpstan#8609

[phpstan-bot]

This pull request has been marked as ready for review.

[staabm]

it seems you are adding a new test-case here, but you did not analyze this file from any of the *Test classes.
you need to make sure that this file is analyzed from the correct *Test class - the one which is testing the rule which emits the error you are trying to fix

[ondrejmirtes]

1. File name needs to be in bug-8609.php format.
2. File needs to be analysed by tests/PHPStan/Rules/PhpDoc/MethodConditionalReturnTypeRuleTest.php.

[ondrejmirtes]

Additionally, we need to test that this actually works. A new file tested in NodeScopeResolverTest would be nice.

[ondrejmirtes]

union isn't the best operation for this. I suggest array_merge instead, like here:

phpstan-src/src/Analyser/NameScope.php

Lines 164 to 167 in b250a8b

	new TemplateTypeMap(array_merge(
	$this->templateTypeMap->getTypes(),
	$map->getTypes(),
	)),

[ondrejmirtes]

1. File name needs to be in bug-8609.php format.
2. File needs to be analysed by tests/PHPStan/Rules/PhpDoc/MethodConditionalReturnTypeRuleTest.php.

[ondrejmirtes]

Finished it myself :) Thank you!