[PATCH 0/2] MR8368: libs/xml2: Import upstream release 2.13.8.

[Daniel Lehman (＠dlehman25)]

import with 2 small changes:
- config.h -> win32config.h
- comment out deprecation to avoid warnings while preserving `xmlThrDefTreeIndentString` (for 8c792c25)

https://testbot.winehq.org/JobDetails.pl?Key=158748