Description:
------------
Memory remains occupied (24 bytes) after pg_connect()/pg_close() call. Calling gc_collect_cycles() does not help.

It kills our daemon script which connects/disconnects to database.

Isolated on Windows 10 but happens on Debian with PHP 5.6.

Test script:
---------------
for ($i = 0; $i < 500; $i++) {
	echo "$i: " . memory_get_usage()."\n";
	pg_close(pg_connect("host=localhost dbname=test"));
}