[jfx11u] RFR: 8306115: Update libxml2 to 2.10.4

[Johan Vos]

8306115: Update libxml2 to 2.10.4
Reviewed-by: kcr, sykora

-------------

Commit messages:
 - 8306115: Update libxml2 to 2.10.4

Changes: https://git.openjdk.org/jfx11u/pull/141/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx11u&pr=141&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8306115
  Stats: 95 lines in 12 files changed: 59 ins; 6 del; 30 mod
  Patch: https://git.openjdk.org/jfx11u/pull/141.diff
  Fetch: git fetch https://git.openjdk.org/jfx11u.git pull/141/head:pull/141

PR: https://git.openjdk.org/jfx11u/pull/141