[lworld] RFR: 8345995: [lworld] Flat arrays need to be redesigned to support new flat layouts [v4]

[Frederic Parain]

> Here's a redesign of flat arrays to support multiple flat layouts (NON_ATOMIC_FLAT, ATOMIC_FLAT, NULLABLE_ATOMIC_FLAT). The patch contains a lot of cleanup and simplification of the flat arrays access code.
> 
> This patch has been tested in interpreted mode only on both x86_64 and aarch64.
> 
> Unfortunately, it currently triggers a number of failures when run with JITs enabled. After a discussion with Tobias, this PR will probably not be integrated until a patch for the JITs is available.
> 
> Regards,
> 
> Fred

Frederic Parain has updated the pull request incrementally with one additional commit since the last revision:

  Fix bad register usage causing mdp corruption

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

Changes:
  - all: https://git.openjdk.org/valhalla/pull/1315/files
  - new: https://git.openjdk.org/valhalla/pull/1315/files/5fe9f5f5..048b88c4

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1315&range=03
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1315&range=02-03

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/valhalla/pull/1315.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1315/head:pull/1315

PR: https://git.openjdk.org/valhalla/pull/1315