Add setend ARM instruction detection for FFmpeg.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@37258 b3059339-0415-0410-9bf9-f77b7e298cf2
Check existence of a demuxer when updating global_sub_size.

The GUI may call mpctx_get_global_sub_info() which forces
updating global_sub_size even if there isn't yet a demuxer.

This closes Trac #2201.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@37259 b3059339-0415-0410-9bf9-f77b7e298cf2