If debug symbols are needed, then pass the respective flag to the
configure script.
Pick-to: 6.9 6.8
Change-Id: I99db92bdd5b7eb896e0d592117a8f218467a4bd7
Reviewed-by: Øystein Heskestad <oystein.heskestad@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
355e0d85eb