Aleix authored Apr 06, 2017 and Brad King committed Apr 20, 2017

Qt is relying on whoever calls moc to include a file with the predefined
values that will be used by the compiler, otherwise moc takes wrong
paths and weird things happen.
Instead, generate an include file and feed it to all mocs to make sure
it's generating correct code.

Co-Author: Sebastian Holtermann <sebholt@xwmw.org>
Fixes: #16640