This PR was merged into the 4.4 branch.Discussion----------[PropertyInfo] add static cache to ContextFactory| Q             | A| ------------- | ---| Branch?       | 4.4| Bug fix?      | no (performance...)| New feature?  | no| BC breaks?    | no| Deprecations? | no| Tests pass?   | yes| Fixed tickets |#32073,api-platform/api-platform#1159| License       | MIT| Doc PR        | noThe issue is very very well described here#32073, and was also discussed a few weeks ago with@dunglas hereapi-platform/api-platform#1159.`ContextFactory::createFromReflector` is heavy, and it's called redundanltyby `Symfony\Component\PropertyInfo\Extractor\PhpDocExtractor` for each propertyand methods. Avoid that by parsing it only once and then use static cacheThis is a quite big performance problem.![Deepin Capture-écran_zone de sélection _20190626142041](https://user-images.githubusercontent.com/84887/60179692-8471c480-981e-11e9-9e3c-3f9c0b83b01b.png)Commits-------063e880 [PropertyInfo] add static cache to ContextFactory

… (mvhirsch)This PR was squashed before being merged into the 7.2 branch.Discussion----------[PropertyInfo] Adds static cache to `PhpStanExtractor`| Q             | A| ------------- | ---| Branch?       | 7.2| Bug fix?      | no (performance)| New feature?  | no <!-- please update src/**/CHANGELOG.md files -->| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->| Issues        |  <!-- prefix each issue number with "Fix #", no need to create an issue if none exists, explain below instead -->| License       | MITI was able to detect a performance penalty when using dozens of traits in even more classes. The `PhpStanExtractor ` creates a `NameScope` every time, but afaik this can be cached like in `PhpDocExtractor` (see#32188).The performance impact is impressive, as it reduces the time needed for my `TestCase` by 30%. See [Blackfire profile comparison](https://blackfire.io/profiles/compare/9eb78784-fa68-4721-9c87-f2be52da2d63/graph).<!--Replace this notice by a description of your feature/bugfix.This will help reviewers and should be a good start for the documentation.Additionally (seehttps://symfony.com/releases): - Always add tests and ensure they pass. - Bug fixes must be submitted against the lowest maintained branch where they apply   (lowest branches are regularly merged to upper ones so they get the fixes too). - Features and deprecations must be submitted against the latest branch. - For new features, provide some code snippets to help understand usage. - Changelog entry should followhttps://symfony.com/doc/current/contributing/code/conventions.html#writing-a-changelog-entry - Never break backward compatibility (seehttps://symfony.com/bc).-->Commits-------9697351 [PropertyInfo] Adds static cache to `PhpStanExtractor`