Revision 1543596

Silence a number of integer size conversion warnings by casting the output
of our rather generic reader functions to the correct target type.

* subversion/libsvn_fs_x/string_table.c
  (svn_fs_x__read_string_table): explicitly cast to the target type
* subversion/libsvn_fs_x/reps.c
  (svn_fs_x__read_reps_container): ditto
* subversion/libsvn_fs_x/noderevs.c
  (svn_fs_x__read_noderes_container): ditto
* subversion/libsvn_fs_x/changes.c
  (svn_fs_x__read_changes_container): ditto
* subversion/libsvn_subr/packed_data.c
  (svn_packed__get_bytes): ditto