- BFN
Merge branch 'PHP-5.4' of git.php.net:php-src into PHP-5.4
Fixed (some of) add/sub.

This worked in PHP 5.4 already, but with the introduction of DateTimeImmutable
this code was not correctly merged.
Merge branch 'PHP-5.5' into PHP-5.6
Merge branch 'PHP-5.6'
Merge branch 'PHP-5.4' into PHP-5.5
Merge branch 'PHP-5.5' into PHP-5.6
Merge branch 'PHP-5.6'