Stop using PREMUL and INV_PREMUL macros

The two macros were replaced with qPremultiply and qUnpremultiply in
Qt 5.3, and this is the last place in Qt the old macros are still used.

Change-Id: Ic1bd1f37a843ffa76e37adfcbbde39fbfbd9ff2a
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>

src/svg/qsvggenerator.cpp

@@ -257,17 +257,17 @@ class QSvgPaintEngine : public QPaintEngine
             if (!constantAlpha) {
                 const qreal spacing = qreal(0.02);
                 QGradientStops newStops;
-                QRgb fromColor = PREMUL(stops.at(0).second.rgba());
+                QRgb fromColor = qPremultiply(stops.at(0).second.rgba());
                 QRgb toColor;
                 for (int i = 0; i + 1 < stops.size(); ++i) {
                     int parts = qCeil((stops.at(i + 1).first - stops.at(i).first) / spacing);
                     newStops.append(stops.at(i));
-                    toColor = PREMUL(stops.at(i + 1).second.rgba());
+                    toColor = qPremultiply(stops.at(i + 1).second.rgba());
 
                     if (parts > 1) {
                         qreal step = (stops.at(i + 1).first - stops.at(i).first) / parts;
                         for (int j = 1; j < parts; ++j) {
-                            QRgb color = INV_PREMUL(INTERPOLATE_PIXEL_256(fromColor, 256 - 256 * j / parts, toColor, 256 * j / parts));
+                            QRgb color = qUnpremultiply(INTERPOLATE_PIXEL_256(fromColor, 256 - 256 * j / parts, toColor, 256 * j / parts));
                             newStops.append(QGradientStop(stops.at(i).first + j * step, QColor::fromRgba(color)));
                         }
                     }