docs: remove reference to src/tools/thread

This directory and the ability to build the thread test independently
were removed in commit 8a2121185b.

Reported-by: e.indrupskaya@postgrespro.ru
Discussion: https://postgr.es/m/160379609706.24746.7506163279454026608@wrigleys.postgresql.org

Backpatch-through: 9.5

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index a88577c7b7c246eb88825b340f3cf5bfd31a75a4..ef9ad50ac60e7aeb020e3d1d6033bd4446785f1f 100644 (file)
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -7739,14 +7739,6 @@ int PQisthreadsafe();
    <application>libpq</application> source code for a way to do cooperative
    locking between <application>libpq</application> and your application.
   </para>
-
-  <para>
-   If you experience problems with threaded applications, run the program
-   in <filename>src/tools/thread</> to see if your platform has
-   thread-unsafe functions.  This program is run by
-   <filename>configure</filename>, but for binary distributions your
-   library might not match the library used to build the binaries.
-  </para>
  </sect1>