Store PhpStorm stub paths relative to the stubs package in the reflection cache

[SvenHerrmann]

fixes #15023

[ondrejmirtes]

I'm skeptical here because this isn't the only thing that's stored with absolute filename in the cache. Why it's a problem here but not in other cases?

[SvenHerrmann]

In the other cases, the absolute path (or a hash of it) is part of the cache key.
So in fact you have two cache items in that cases - one for each absolute project path

e.g.

phpstan-src/src/Reflection/BetterReflection/SourceLocator/OptimizedSingleFileSourceLocator.php

Lines 71 to 73 in 4c8b9ac

	$variableCacheKey = $this->getVariableCacheKey($this->fileName);
	$presentSymbolsCacheKey = sprintf('osfsl-%s-presentSymbols', $this->fileName);
	$cached = $this->cache->load($presentSymbolsCacheKey, $variableCacheKey);

(cache key depends on fileName)

vs.

phpstan-src/src/Reflection/BetterReflection/SourceLocator/CachedPhpInternalSourceLocator.php

Lines 54 to 57 in 4c8b9ac

	$cacheKey = sprintf('phpinternal-%s-%s', $identifier->getType()->getName(), $name);
	$variableCacheKey = $this->getVariableCacheKey();
	$cached = $this->cache->load($cacheKey, $variableCacheKey);

phpstan-src/src/Reflection/BetterReflection/SourceLocator/CachedPhpInternalSourceLocator.php

Lines 95 to 103 in 4c8b9ac

	private function getVariableCacheKey(): string
	{
	return $this->variableCacheKey ??= sprintf(
	'v1-%s-%s-%s',
	ComposerHelper::getBetterReflectionVersion(),
	ComposerHelper::getPhpStormStubsVersion(),
	$this->phpVersion->getVersionString(),
	);
	}

(cache key only depends on versions)

I assume, the path was omitted as part of the cache key, as normally you wouldn't have a real file for an internal function.

[ondrejmirtes]

I'd like an E2E test that shows the problem in e2e-tests.yml and e2e/ directory instead.

It's possible I'll just solve it by reverting the cache, the wins were small anyway, or maybe with a different solution than this PR presents.