QMenu::exec opens a blocking loop, which is problematic for webassembly.
Replace with QMenu::popup, and reset the down-state of the button when
the menu is about to hide. QMenu emits aboutToHide immediately before
existing the event loop in the hideEvent override, so the timing is the
same.
Change-Id: Iccb418d10fcb25f6ad1f73f9cdce6ea6581bd73b
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
7199498fb9