Add .clang-tidy configuration file to provide LLVM-optimized defaults for
clang-tidy.

Reviewers: chandlerc, djasper

Reviewed By: djasper

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5236

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217365 91177308-0d34-0410-b5e6-96231b3b80d8