Add the optional flag `wayland?` in `gdm-configuration` to launch GDM with
Wayland, enabling the use of Wayland sessions with GDM.
* gnu/packages/patches/gdm-remove-hardcoded-xwayland-path.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/gnome.scm (gdm): Use it.
* gnu/services/xorg.scm (<gdm-configuration>)[wayland?]: New field.
(gdm-configuration): Honor it.
(gdm-shepherd-service): Add the XCURSOR_PATH environment variable.
* doc/guix.texi (X Window): Document it
Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>
Josselin Poiret