clang-format: Avoid bad line break.

Before:
  int
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaa(const
                                typename aaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaa);

After:
  int aaaaaaaaaaaaaaaaaaaaaaaaaaaaa(
      const typename aaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaa);

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@215442 91177308-0d34-0410-b5e6-96231b3b80d8