Add support for "array of type"

Summary:
When you use foreach ( $a as $e ), when $a is an 'iterator of x', then type of $e is set to 'x'.

This patch add a syntax in @param and @return to specifiy that $a is an 'array of x`: @param x[].
This patch add support when $a is an 'array of x'.

Reviewers: pprkut

Reviewed By: pprkut

Subscribers: pprkut, kdevelop-devel

Tags: KDevelop

Differential Revision: https://phabricator.kde.org/D24921