Without treating -force_load as an option with an argument, we end up
leaving stray -force_loads in the linker line, resulting in build
failures when the following option is a random library then treated
as a file path.
Task-number: QTBUG-66091
Change-Id: I352c50ab67e32ef6b2b5c6a4f90455b20034e207
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>