Description:
------------
The optional parameters of the functions listed below are described as required by reflection.

locale_get_display_language
locale_get_display_name
locale_get_display_region
locale_get_display_script
locale_get_display_variant
locale_filter_matches
locale_lookup

Test script:
---------------
<?php

$funcs = [
'locale_get_display_language',
'locale_get_display_name',
'locale_get_display_region',
'locale_get_display_script',
'locale_get_display_variant',
'locale_filter_matches',
'locale_lookup',
];

foreach ($funcs as $func) {
    $rf = new ReflectionFunction($func);
    printf("%s: %d, %d\n", $func, $rf->getNumberOfParameters(), $rf->getNumberOfRequiredParameters());
}

Expected result:
----------------
locale_get_display_language: 2, 1
locale_get_display_name: 2, 1
locale_get_display_region: 2, 1
locale_get_display_script: 2, 1
locale_get_display_variant: 2, 1
locale_filter_matches: 3, 2
locale_lookup: 4, 2

Actual result:
--------------
locale_get_display_language: 2, 2
locale_get_display_name: 2, 2
locale_get_display_region: 2, 2
locale_get_display_script: 2, 2
locale_get_display_variant: 2, 2
locale_filter_matches: 3, 3
locale_lookup: 4, 4