RFR: 8237889: Update libxml2 to version 2.9.10

[Arun Joseph]

We currently use libxml2 version 2.9.9. We should update to the latest stable release 2.9.10.

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Commits:
 - eaf8d1b1: 8237889: Update libxml2 to version 2.9.10

Changes: https://git.openjdk.java.net/jfx/pull/120/files
 Webrev: https://webrevs.openjdk.java.net/jfx/120/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8237889
  Stats: 2942 lines in 70 files changed: 1242 ins; 992 del; 708 mod
  Patch: https://git.openjdk.java.net/jfx/pull/120.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/120/head:pull/120

PR: https://git.openjdk.java.net/jfx/pull/120