[clang-format] Make NoLineBreakFormatter respect MustBreakBefore

Summary:
This patch makes NoLineBreakFormatter to insert a break before tokens where
MustBreakBefore is true.

Reviewers: djasper

Reviewed By: djasper

Subscribers: cfe-commits, klimek

Differential Revision: https://reviews.llvm.org/D33238

llvm-svn: 303332