bash: Hide diff-stages from completion.
bash: Hide diff-stages from completion.

Apparently nobody really makes use of git-diff-stages, as nobody
has complained that it is not supported by the git-diff frontend.
Since its likely this will go away in the future, we should not
offer it as a possible subcommand completion.

Signed-off-by: Shawn O. Pearce <f01032651c12a22b2103346ba96b3b6b231f9d3c@spearce.org>
Signed-off-by: Junio C Hamano <dc50d1021234060e53ec42a77d526afa2fe07479@cox.net>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git