clang-format: Make indentation after "<<" more consistent.

Before:
  Diag(aaaaaaaaaaaaaaaaaaaa, aaaaaaaa)
      << aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(
	  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa);
  Diag(aaaaaaaaaaaaaaaaaaaa, aaaaaaaa)
      << aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(
	     aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa)
      << aaa;

After:
  Diag(aaaaaaaaaaaaaaaaaaaa, aaaaaaaa)
      << aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(
	     aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa);
  Diag(aaaaaaaaaaaaaaaaaaaa, aaaaaaaa)
      << aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(
	     aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa)
      << aaa;

llvm-svn: 260517