Memory usage for svn_io_remove_dir was going through the roof when removing a large directory (e.g. bumping into a 128 MB resource limit in svn_fs_fs__purge_txn when committing 89482 files).  Fix its pool usage to avoid this.  Thanks to kfogel for review and cleanup suggestions.
Memory usage for svn_io_remove_dir was going through the roof when
removing a large directory (e.g. bumping into a 128 MB resource
limit in svn_fs_fs__purge_txn when committing 89482 files).  Fix
its pool usage to avoid this.  Thanks to kfogel for review and
cleanup suggestions.

* subversion/libsvn_subr/io.c
  (svn_io_remove_dir): Allocate path_apr and this_dir directly in the
  input pool instead of the subpool.  Use subpool instead of pool in
  the loop, clearing it on each iteration.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@851775 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion