Revert removal of trace_userlocks, because userlocks aren't gone.

Robert Haas <rhaas@postgresql.org>

Commit: 71b2b657c034743f81ae7906d7b0fcc8e9a0a6a3
Author: Robert Haas <rhaas@postgresql.org>
Date: 2011-11-10T22:54:27Z
Releases: 9.2.0
Revert removal of trace_userlocks, because userlocks aren't gone.

This reverts commit 0180bd6180511875db046bf8ddcaa633a2952dfd.
contrib/userlock is gone, but user-level locking still exists,
and is exposed via the pg_advisory* family of functions.

Files