[clang-tools-extra] r215839 - First version of a clang-rename tool.

[Rafael Espíndola]

> Note that we do want to migrate (most of) clang-format's tests to lit tests
> (because most of them are integration tests), but that's a different topic.

Well, that was the topic of my reply :-)

When gtest is appropriate, do use it. My request was just to not build
another large test set that we want to migrate in the future.

Cheers,
Rafael