This patch is a minor rework/repost of 
http://sourceware.org/ml/gdb-patches/2011-11/msg00836.html , which Kwok 
got approved last November but then fell through the cracks.  I updated 
it, tweaked the docs per Eli, and add a simple sanity test.  It all 
seems pretty obvious, but on the off-chance that somebody sees something 
I missed, I'll wait a day to commit it.

Stan

2012-05-22  Stan Shebs <stan@codesourcery.com>
         Kwok Cheung Yeung <kcy@codesourcery.com>

     * Makefile.in (SUBDIR_MI_OBS): Add mi-cmd-info.o.
     (SUBDIR_MI_SRCS): Add mi-cmd-info.c.
     (mi-cmd-info.o): New rule.
     * osdata.h (info_osdata_command): New declaration.
     * osdata.c (info_osdata_command): Change to non-static.
     * mi/mi-cmds.h (mi_cmd_info_os): New declaration.
     * mi/mi-cmds.c (mi_cmds): Add -info-os MI command.
     * mi/mi-cmd-info.c: New file.

     * gdb.texinfo (Miscellaneous GDB/MI Commands): Document -info-os.

     * gdb.mi/mi-info-os.exp: New file.