ping @symfony/deciders (we need this to make the test suite pass again for all branches on Travis)

Thank you@xabbuh.

Just to add this as a side-note: I also had a problem that was fixed by these lines here. My usecase was like following:

I had a class in my self-written extension, that extended a native PHP class. Thereby the parent-class hasn't had a valid includable file. The result now was, that the cache, containing the dependencies merged in a single file, was rebuild all the time, because the timestamp of that file couldn't be checked.