Summary: Adds support for formatting for and while loops.

Reviewers: djasper, klimek

Reviewed By: klimek

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D174

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@169387 91177308-0d34-0410-b5e6-96231b3b80d8