Array methods that manipulate the array they are called on always have
side effects, on that array. In order to optimize them out we'd have to
do some more involved tracking of affected values.
Amends commit e846864151
Fixes: QTBUG-126834
Pick-to: 6.8 6.7
Change-Id: Ia4395ea21e89590e6ffe95e236f70b5e64402f5e
Reviewed-by: Olivier De Cannière <olivier.decanniere@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
ae76c8f428