In FSX, release potentially large internal allocations before returning from the respective FS API function.
In FSX, release potentially large internal allocations before returning
from the respective FS API function.

It may be difficult for the FS API user to decide which of the functions
may allocate a larger amount of temporary memory.  Hence, they might not
clean up their scratch pool very often.  But whenever FSX *knows* that
its code involves opening multiple files or manipulating larger buffers,
it can make sure to use a sub-pool around that section with minimal added
overhead.

* subversion/libsvn_fs_x/transaction.c
  (with_some_lock_file): Whenever we lock the repo, we will probably write
                         data.  That's usally expensive and we give it a
                         separate sub-pool.
  (svn_fs_x__change_txn_props): Properties can be large as well, therefore
                                make sure to clean them up asap.

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1710349 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion