Revision 1656694

Rename svn_ra_dup_session() (public api) to svn_ra__dup_session (private api).

No functional changes.

* subversion/include/private/svn_ra_private.h
  (svn_ra__dup_session): New function.

* subversion/include/svn_ra.h
  (svn_ra_dup_session): Remove function

* subversion/libsvn_client/diff.c
  (includes): Add svn_ra_private.h.
  (diff_repos_repos): Update caller.

* subversion/libsvn_ra/ra_loader.c
  (svn_ra_dup_session): Rename to...
  (svn_ra__dup_session): ... this.
  (svn_ra_stat): Update caller (in svnserve fallback code).