Add a triple so that this passes on OS X.

I am surprised I am the first one to notice this.
clang-format: Slightly adapt decision of when to break before <<.

Before:
  Diag(aaaaaaaaaaaaaaaaaaaa, aaaaaaaa) << aaaaaaaaaaaaaaaaaaaaaaaaa(
                                              aaaaaaaaaaaaa);

After:
  Diag(aaaaaaaaaaaaaaaaaaaa, aaaaaaaa)
      << aaaaaaaaaaaaaaaaaaaaaaaaa(aaaaaaaaaaaaa);