Merge commit '9c1e1114'

* commit '9c1e1114':
  flac: Convert to the new bitstream reader
  bitstream: Avoid undefined behavior in bitstream_skip()

This commit is a noop, see
https://ffmpeg.org/pipermail/ffmpeg-devel/2017-April/209609.htmlMerged-by: James Almer <jamrial@gmail.com>