Integrated: Merge lworld

[Vicente Romero]

Merge branch 'lworld' into lw5_merge_lworld

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Commit messages:
 - Merge branch 'lworld' into lw5_merge_lworld
 - Merge jdk
 - 8319318: bufferedStream fixed case can be removed
 - 8319556: Harmonize interface formatting in the FFM API
 - 8319378: Spec for j.util.Timer::purge and j.util.Timer::cancel could be improved
 - 8315680: java/lang/ref/ReachabilityFenceTest.java should run with -Xbatch
 - 8305814: Update Xalan Java to 2.7.3
 - 8319573: Change to Visual Studio 17.6.5 for building on Windows at Oracle
 - 8319338: tools/jpackage/share/RuntimeImageTest.java fails with -XX:+UseZGC
 - 8319436: Proxy.newProxyInstance throws NPE if loader is null and interface not visible from class loader
 - ... and 147 more: https://git.openjdk.org/valhalla/compare/1e7c8398...79946f51

The webrevs contain the adjustments done while merging with regards to each parent branch:
 - lw5: https://webrevs.openjdk.org/?repo=valhalla&pr=989&range=00.0
 - lworld: https://webrevs.openjdk.org/?repo=valhalla&pr=989&range=00.1

Changes: https://git.openjdk.org/valhalla/pull/989/files
  Stats: 40174 lines in 1489 files changed: 21005 ins; 7536 del; 11633 mod
  Patch: https://git.openjdk.org/valhalla/pull/989.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/989/head:pull/989

PR: https://git.openjdk.org/valhalla/pull/989