Since symlinks to shell completion files are installed, it is useful to remove
them during the uninstallation, especially when they point to files that are
removed by 'guix-install.sh --uninstall'.
* etc/guix-install.sh (sys_delete_shell_completion): Create.
(sys_create_shell_completion): hardcode files being installed.
(sys_customize_bashrc): call sys_delete_shell_completion.
Change-Id: I70008bb55e7e1604f0c485c798460e160af7c9e5
Signed-off-by: Ludovic Courtès <ludo@gnu.org>