clang-format: Understand 'typename' in placement new.

Before:
  new (aaaaaaaaaaaaaaaaaaaaaaaaaa(
      aaaaaaaaaaaaaaaaaaaaaaa)) typename aaaaaaaaaaaaaaaaaaaaaaaa();

After:
  new (aaaaaaaaaaaaaaaaaaaaaaaaaa(aaaaaaaaaaaaaaaaaaaaaaa))
      typename aaaaaaaaaaaaaaaaaaaaaaaa();

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@214300 91177308-0d34-0410-b5e6-96231b3b80d8