Simplify new test suite handling of passwordcheck

This changes the use of a custom configuration file to enforce the value
of preload_shared_libraries to simply load the library during the tests.
This removes the restriction of running installcheck on the tests, and
simplifies its makefile contrary to what has been introduced in af7211e9.

Author: Michael Paquier <michael.paquier@gmail.com>

contrib/passwordcheck/Makefile

@@ -8,10 +8,7 @@ PGFILEDESC = "passwordcheck - strengthen user password checks"
 # PG_CPPFLAGS = -DUSE_CRACKLIB '-DCRACKLIB_DICTPATH="/usr/lib/cracklib_dict"'
 # SHLIB_LINK = -lcrack
 
-REGRESS_OPTS = --temp-config $(srcdir)/passwordcheck.conf
 REGRESS = passwordcheck
-# disabled because these tests require setting shared_preload_libraries
-NO_INSTALLCHECK = 1
 
 ifdef USE_PGXS
 PG_CONFIG = pg_config

contrib/passwordcheck/expected/passwordcheck.out

+LOAD 'passwordcheck';
 CREATE USER regress_user1;
 -- ok
 ALTER USER regress_user1 PASSWORD 'a_nice_long_password';

contrib/passwordcheck/passwordcheck.conf

-shared_preload_libraries = 'passwordcheck'

contrib/passwordcheck/sql/passwordcheck.sql

+LOAD 'passwordcheck';
+
 CREATE USER regress_user1;
 
 -- ok