qt_findAtNxFile(): account for .9 (9-patch image) extensions

Currently a file with a .9.png extension will only have its @2x variant
found if it follows this format:

foo.9@2x.png

Since ".9" should be considered part of the file suffix, it should
ideally be able to look like this and still be picked up:

foo@2x.9.png

This patch makes qt_findAtNxFile() account for .9.* extensions.

This is needed for the image-based style support in Qt Quick Controls
2, which uses 9-patch images.

qmlbench benchmark results using
benchmarks\auto\creation\quick.image\delegates_image.qml with
QT_SCALE_FACTOR=2 show no difference in performance after this patch
is applied.

[ChangeLog][QtGui] High DPI variants of 9-patch images can now be
loaded using the following syntax: "foo@2x.9.png"

Change-Id: I6d1384113bef21b4fe85a104ee6b16869c93b077
Reviewed-by: J-P Nurmi <jpnurmi@qt.io>
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

0 files changed, 0 insertions, 0 deletions