Fix the EntityRegenerator on Mac

[dunglas]

On Mac, an instance of Doctrine\Common\Persistence\Mapping\MappingException is thrown by Doctrine when a mapping file references a non-existing class. Currently, the code only catches Doctrine\ORM\Mapping\MappingException instances.

This PR makes the tests green on Mac (#167 (comment)). This also probably fixes a real bug.

I've no idea why Doctrine throws a different exception on Mac than on Linux.

[dunglas]

Excluding this file on PHP 7 makes Travis happy!

This cause PHP CS Fixer's linting to fail on PHP 7 because this syntax is supported only since PHP 7.1. However the make:entity command already requires 7.1.
Do you want me to use multiple catch blocks or just to ignore this file in the PHP CS config on PHP 7?

[andrewtch]

The exception | exception syntax is not supported in php 7.0 (and the bundle does support it).

[dunglas]

@andrewtch see #179 (comment)

make:entity already requires PHP 7.1: https://github.com/symfony/maker-bundle/blob/master/src/Maker/MakeEntity.php#L113

[andrewtch]

@dunglas , ah, indeed. The current fix seems to work for me just fine.

[weaverryan]

Fantastic! Super weird, but the code/fix gives us code that still makes sense: if there’s a mapping exception in general, fallback to the disconnected metadata lookup.

Hopefully this will unblock some things!