Process member properties/calls for unsure types in PHP

Summary: In PHP, you can only access properties and call member functions on objects. So this diff looks at an `UnsureType` and, if it contains //exactly// one `StructureType`, decides to interpret the variable as that object for this access/call.

Reviewers: #kdevelop

Subscribers: kdevelop-devel, #kdevelop

Tags: #kdevelop

Differential Revision: https://phabricator.kde.org/D6923