Merge the 2018-09-05 SPL branch from AOSP-Partner

* security-aosp-nyc-mr2-release:
  RESTRICT AUTOMERGE: Update libxml2 to 2.9.8
  DO NOT MERGE: Add validation for eternal enities
  DO NOT MERGE: Use correct limit for port values
  DO NOT MERGE: Heap buffer overflow in xmlAddID
  DO NOT MERGE: fix for the XPath nodeTab use-after-free bug from nmehta@
  DO NOT MERGE: Apply upstream Chromium patch for encoding changes
  DO NOT MERGE: Fix XPointer paths beginning with range-to
  DO NOT MERGE: Disallow namespace nodes in XPointer ranges

Conflicts: Although the SPL branch is supposed to introduce changes on
top of the release tag, it does not merge cleanly. Even after a
`git merge -X theirs ...`, parser.c remained in an unclean state. Fixed
that by an additional `git checkout HEAD^2 -- .`, amending the merge.

Change-Id: Ifd5680aa492cc168d017f652d9a3797db716a894