[clang-tidy] Add loop-convert check to clang-tidy.

Move LoopConvert from clang-modernize to modernize module in clang-tidy.

http://reviews.llvm.org/D12076

Patch by Angel Garcia!

llvm-svn: 245427
GitOrigin-RevId: 0497084b69885b239bb7d7b9259405c4481ab39d
10 files changed