Description:
------------
Execute the test script:

 - php -d zend.assertions=1 test.php
 - php -d zend.assertions=0 test.php
 - php -d zend.assertions=-1 test.php

`assert()` doesn't respect the namespace fallback, but assumes unqualified calls are equivalent to `\assert()` and optimize it away / jump around it with assertions disabled.

This is unfortunate, as few people use `\assert()` over `assert()` and wouldn't gain zero-cost assertions without this behavior.

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

namespace Test {
    function assert() {
        global $foo;

        $foo = true;
    }
}

namespace Test {
    assert();

    var_dump(isset($foo));
}

Expected result:
----------------
bool(true)

Actual result:
--------------
bool(false)