As of PHP 7.3.0, unlinking files with open handles is possible on
Windows, but these file entries are still blocked until all open
handles are closed.  Since this test doesn't require to write to the
same file, we use three separate files.

We also add the missing skip check for XMLReader.

This reverts commit d8ad2f4695ebd6dc2d4e668d9baeac1c071791a6.

These functions don't expect any arguments, so we check that none are
given.

Normalization include:
- Use dnl for everything that can be ommitted when configure is built in
  favor of the shell comment character # which is visible in the output.
- Line length normalized to 80 columns
- Dots for most of the one line sentences
- Macro definitions include similar pattern header comments now