clang-format: Understand that breaking before lambdas is fine.

Before:
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa([](
      const aaaaaaaaaa &a) { return a; });

After:
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(
      [](const aaaaaaaaaa &a) { return a; });

llvm-svn: 211575