Build the tree in only one loop.
clangbackend generates tokens almost as fast as it
did before (about 10% slower in general).
Broken documents are more affected and take much more
time (about 300%) but it's better to have this time spent
on backend side then in QtC itself.
Task-number: QTCREATORBUG-20205
Change-Id: I34c58bca30c4494005a029abd82c7e612ecd6fb9
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>
