PHP ext/collections skeleton not linking

config.m4

PHP_ARG_ENABLE(collections, whether to enable Collections support,
  [  --enable-collections    Enable Collections support])


if test "$PHP_COLLECTIONS" = "yes"; then
  AC_DEFINE(HAVE_COLLECTIONS, 1, [Whether you have Collections support])
  PHP_NEW_EXTENSION(collections, collections.c, $ext_shared)
fi

php_collections.c

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "php.h"
#include "php_collections.h"


zend_module_entry collections_module_entry = {
	STANDARD_MODULE_HEADER,
	PHP_COLLECTIONS_EXTNAME,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	PHP_COLLECTIONS_VERSION,
	STANDARD_MODULE_PROPERTIES
};

#ifdef COMPILE_DL_COLLECTIONS
ZEND_GET_MODULE(collections)
#endif

php_collections.h

#ifndef PHP_COLLECTIONS_H
#define PHP_COLLECTIONS_H 1

#define PHP_COLLECTIONS_VERSION "0.1.0"
#define PHP_COLLECTIONS_EXTNAME "collections"

extern zend_module_entry collections_module_entry;
#define phpext_collections_ptr &collections_module_entry

#endif