Support of Class::{expr}() syntax from Php 5.4

Summary:
PHP 5.4 features
[[ https://bugs.kde.org/show_bug.cgi?id=305779 | bug305779 ]]

Reviewers: kfunk, mwolff, zhigalin, #kdevelop, pprkut

Reviewed By: mwolff, zhigalin, #kdevelop, pprkut

Subscribers: kdevelop-devel, #kdevelop

Tags: #kdevelop

Differential Revision: https://phabricator.kde.org/D4902