This release relaxes [`doctrine/common`](https://github.com/doctrine/common) requirements in order to allow installation of versions that support PHP 7.1 features in proxy class generation. Please note that a similar requirement relaxation still needs to be applied to [`doctrine/dbal`](https://github.com/doctrine/dbal) in order to allow installation of the latest `doctrine/common` versions. [#6156](https://github.com/doctrine/doctrine2/pull/6156) This version also backports some fixes around the eviction of the second level cache entries of inverse side associations in one-to-many - many-to-one mappings. [#6159](https://github.com/doctrine/doctrine2/pull/6159) Further fixes were applied in order to have child classes in inheritance mapping share the same timestamp region when the second level cache is enabled. [#6028](https://github.com/doctrine/doctrine2/pull/6028) Also, `Doctrine\ORM\EntityManager#merge()` now triggers `Doctrine\ORM\Events::prePersist` listeners with the merged entity state whenever an internal `Doctrine\ORM\UnitOfWork#persist()` call is implied. [#6177](https://github.com/doctrine/doctrine2/pull/6177). Total issues resolved: **8** - [5570: Fix PrePersist EventListener when using merge instead of persist](https://github.com/doctrine/doctrine2/pull/5570) - [6028: Make child entity share the timestamp region with parent class](https://github.com/doctrine/doctrine2/pull/6028) - [6110: Clear $this->collection even when empty, to reset keys](https://github.com/doctrine/doctrine2/pull/6110) - [6156: Allow doctrine/common 2.7](https://github.com/doctrine/doctrine2/pull/6156) - [6159: #5821 Backport #1551 - Fixed support for inverse side second level cache](https://github.com/doctrine/doctrine2/pull/6159) - [6174: Merging a new entity with PrePersist event make changes in callback not be considered](https://github.com/doctrine/doctrine2/pull/6174) - [6177: Fix #6174 #5570: merging new entities should also trigger prepersist lifecycle callbacks with merged entity data](https://github.com/doctrine/doctrine2/pull/6177) - [6178: Backport #6177 - fix #6174 #5570: merging new entities should also trigger prepersist lifecycle callbacks with the merged data](https://github.com/doctrine/doctrine2/pull/6178)