[lworld+vector] RFR: Merge lworld [v2]

[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

Jatin Bhateja has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 22 commits:

 - Adding space.
 - Changes for alignment with new code model.
 - Merge branch 'lworld' of http://github.com/openjdk/valhalla into merge_from_lworld
 - JDK 8327435: [lworld+vector] Align existing Vector API support with JEP 401
 - Merge lworld
 - 8319945: [lworld+vector] Fix vector api jtreg crash with "-XX:-EnableVectorSupport"
   
   Reviewed-by: jbhateja
 - 8319972: [lworld+vector] Enable intrinsification of Unsafe.finishPrivateBuffer.
   
   Reviewed-by: xgong
 - 8319971: [lworld+vector] Fallback implementation cleanups.
   
   Reviewed-by: xgong
 - 8311675: [lworld+vector] Max Species support.
   
   Reviewed-by: xgong
 - 8317699: [lworld+vector] Fix Vector API tests crash with "assert(vbox->is_Phi()) failed: should be phi"
   
   Reviewed-by: jbhateja
 - ... and 12 more: https://git.openjdk.org/valhalla/compare/e01ec832...08ea01fc

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

Changes: https://git.openjdk.org/valhalla/pull/1073/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1073&range=01
  Stats: 12033 lines in 267 files changed: 4581 ins; 2627 del; 4825 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