[PATCH] msxml3: Allow DOMDocument in VT_DISPATCH slot for put_output.

[Jefferson Carpenter]

Regarding locking the DOMDocument while it is being written to:

It looks like DOMDocument is meant to be used in a single-threaded 
manner[1], so it should be all right to just grab an interface and not 
worry about threads attempting to manipulate the document while it is 
being written to by an mxwriter.

For how to lock it, unless anyone has a better idea I think it would 
work to add an IWineXMLDOMDocumentLock interface with lock() and 
unlock() methods, and output a FIXME if this interface is unavailable.

thanks,
Jefferson

[1] 
https://docs.microsoft.com/en-us/previous-versions/windows/desktop/ms756987(...