The benchmark simply calls QRegularExpression's public API methods, so
that we can assess how changes to the implication impact performance.
(Its addition is prompted by evaluation of whether adding a move
constructor saves more or less than the resulting need for
d-pointer null-checks costs.)
Task-number: QTBUG-86634
Change-Id: Idef775ef6cf9f9ded3ce7ba5b85e460571d12756
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>