RFR: Merge jdk:master

[Kevin Rushforth]

Manual merge of `jdk/master` into `lanai/master` since the nightly auto-merge process is offline (see
[SKARA-764](https://bugs.openjdk.java.net/browse/SKARA-764)).

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

Commit messages:
 - Merge jdk:master
 - 8254795: Remove obsolete template files
 - 8254623: gc/g1/TestHumongousConcurrentStartUndo.java still fails sometimes
 - 8254855: Clean up and remove unused code in vmIntrinsics
 - 8254695: G1: Next mark bitmap clear not cancelled after marking abort
 - 8254161: Prevent instantiation of EnumSet subclasses through deserialization
 - 8254814: [Vector API] Fix an AVX512 crash after JDK-8223347
 - 8251535: Partial peeling at unsigned test adds incorrect loop exit check
 - 8254125: Assertion in cppVtables.cpp during builds on 32bit Windows
 - 8254369: Node::disconnect_inputs may skip precedences
 - ... and 160 more: https://git.openjdk.java.net/lanai/compare/38e78cde...7f3252b9

The webrevs contain the adjustments done while merging with regards to each parent branch:
 - master: https://webrevs.openjdk.java.net/?repo=lanai&pr=119&range=00.0
 - jdk:master: https://webrevs.openjdk.java.net/?repo=lanai&pr=119&range=00.1

Changes: https://git.openjdk.java.net/lanai/pull/119/files
  Stats: 330930 lines in 1108 files changed: 313218 ins; 11374 del; 6338 mod
  Patch: https://git.openjdk.java.net/lanai/pull/119.diff
  Fetch: git fetch https://git.openjdk.java.net/lanai pull/119/head:pull/119

PR: https://git.openjdk.java.net/lanai/pull/119