Subject: [PATCH] archiver: Use 'sources' subdirectory in WORKDIR when
 creating archives

* archiver can sometimes overwrite or remove some files which are
  needed by other tasks.

  This happens in cases where file referenced in SRC_URI aren't
  unpacked and are used by other tasks directly from WORKDIR

  def archive_sources(d, stage_name): downloads sources from
  SRC_URI again to WORKDIR in order to create source tarball from them
  (normally it's ok, because source tarball is directly unpacked from
  DL_DIR so never stays in WORKDIR).

  def archive_sources_patches(d, stage_name): then creates the tarball
  itself and moves source and patch tarballs to deploy with:
  move_tarball_deploy(d, [source_tar_name, patch_tar_name])

  But in cases where source_tar_name == "required" file we're using:
    1) do_unpack downloads "required" from DL_DIR to WORKDIR,
    2) archive_sources overwrites it with another copy,
    3) archive_sources_patches removes it,
    4) do_deploy fails because it wants to install now non-existent
       ${WORKDIR}/required