[lworld+vector] RFR: Merge lworld

[Jatin Bhateja]

Merge from lworld to bring in changes w.r.t to new code model as per revised JEP 401 specification.

All the Vector API and Valhalla jtreg tests are passing at various AVX levels.

There are few failures with -XX:+DeoptimizeALot, explicit sub-tasks for issues to be addressed post merge have been added to existing bug report [JDK-8327435](https://bugs.openjdk.org/browse/JDK-8327435) related to JEP alignment.

Best Regards,
Jatin

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Commit messages:
 - Adding space.
 - Changes for alignment with new code model.
 - Merge branch 'lworld' of http://github.com/openjdk/valhalla into merge_from_lworld
 - 8329196: [lworld] More fixes to value object construction in C2
 - [lworld] Fixing compiler tests failing after JDK-8328543
 - 8329795: [lworld] Remove the jdk internal ValhallaFeatures test api
 - 8329218: [lworld] Arrays.copyOf and Arrays.copyOfRange support for null-restricted arrays
 - 8328543: [lworld] Library and test updates to use --enable-preview instead of ValhallaFeatures
 - 8329400: [lworld] add a test to check that IllegalMonitorStateException is thrown for value objects
 - 8304168: [lworld] CDS tests fail with --enable-preview patched value classes
 - ... and 772 more: https://git.openjdk.org/valhalla/compare/ff8a4159...08ea01fc

The webrevs contain the adjustments done while merging with regards to each parent branch:
 - lworld+vector: https://webrevs.openjdk.org/?repo=valhalla&pr=1073&range=00.0
 - lworld: https://webrevs.openjdk.org/?repo=valhalla&pr=1073&range=00.1

Changes: https://git.openjdk.org/valhalla/pull/1073/files
  Stats: 777910 lines in 4901 files changed: 158514 ins; 525732 del; 93664 mod
  Patch: https://git.openjdk.org/valhalla/pull/1073.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1073/head:pull/1073

PR: https://git.openjdk.org/valhalla/pull/1073