Add wxImage::Rotate180() function.

Closes #12679.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66146 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/image.h

@@ -728,6 +728,13 @@ public:
     */
     wxImage Rotate90(bool clockwise = true) const;
 
+    /**
+        Returns a copy of the image rotated by 180 degrees.
+
+        @since 2.9.2
+    */
+    wxImage Rotate180() const;
+
     /**
         Rotates the hue of each pixel in the image by @e angle, which is a double in
         the range of -1.0 to +1.0, where -1.0 corresponds to -360 degrees and +1.0