clang-format: Properly indent ObjC calls wrapped before first selector

Before:
  [self // break
      a:a
     aa:aa
  aaaaa:aaa];

After:
  [self // break
          a:a
         aa:aa
      aaaaa:aaa];

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@194241 91177308-0d34-0410-b5e6-96231b3b80d8