Demo of Symfony DI bug for singly implemented interfaces whose implementation has no constructor arguments

Run

• Run composer install followed by php index.php.
• Expected output is "Dump with following die inside factory - execution should reach here and stop." due to the dump and die within \App\SingleImplementationFactory::create.
• Actual output is "Execution should never reach here due to the dump and die within \App\SingleImplementationFactory::create." because \App\SingleImplementationFactory::create never appears to be called and so the dump at the end of index.php is reached.

Other Scenarios

• Adding a constructor argument to \App\SingleImplementation makes the desired behaviour happen (factory is called).
• Adding a second (unused) class that implements the interface \App\SinglyImplementedInterface also makes the desired behaviour happen.

Confirmed Versions

• Have tested with 4.4 and 5.0 and confirmed the same behaviour occurs in both.
• 4.3.8 doesn't have the issue.

Linked Issues

• The nature of the bug makes it seem likely it is connected to symfony/symfony#34361 based on the commit message that addressed that bug https://github.com/symfony/symfony/commit/afdb89fe3c16f965bf194007bb409da9b4b255b8.