Apply clang format as proposed in T53211.
For details on usage and instructions for migrating branches
without conflicts, see:
https://wiki.blender.org/wiki/Tools/ClangFormat
This reduces stress on the the stack memory which could be really handy
on certain operation systems which applies strict limits on the stack.
Reviewers: brecht, juicyfruit, dingto
Reviewed By: brecht, juicyfruit, dingto
Differential Revision: https://developer.blender.org/D1656