Add a test for rotated cross-fade nodes

This one checks that we don't apply the modelview
transform twice with cross-fades.

testsuite/gsk/compare/cross-fade-in-rotate.node

@@ -0,0 +1,14 @@
+transform {
+  transform: rotate(90);
+  child: cross-fade {
+    progress: 0;
+    start: color {
+      bounds: 25 0 25 50;
+      color: rgb(255,0,0);
+    }
+    end: color {
+      bounds: 0 0 25 50;
+      color: rgb(0,0,0);
+    }
+  }
+}

testsuite/gsk/meson.build

@@ -34,6 +34,7 @@ compare_render_tests = [
   'color-matrix-identity',
   'color-matrix-parsing',
   'cross-fade-in-opacity',
+  'cross-fade-in-rotate',
   'css-background',
   'empty-blend',
   'empty-blur',