Support case sensitve file systems again.

Releases: master, 8.7
Resolves: #80814
Change-Id: I82274b328e9cfa75fb35360145d7a668d1270dc3
Reviewed-on: https://review.typo3.org/52965


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>