RFR: Merge lworld [v2]

[Vicente Romero]

> Merge branch 'lworld' into lw5

Vicente Romero has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 28 additional commits since the last revision:

 - Merge branch 'lworld' into lw5_merge_lworld
 - Merge lworld
 - Merge lworld
 - 8314913: [lw5] null restrictions can only be applied to value classes
 - 8314899: [lw5] rename j.l.NonAtomic to j.l.LooselyConsistentValue
 - Merge lworld
 - 8314181: [lw5] the check for illegal circularity should only be done if value classes are available
 - 8314165: [lw5] check for illegal circularity at class loading time
 - Merge lworld
 - [lw5] regression test cleanup, relocation
 - ... and 18 more: https://git.openjdk.org/valhalla/compare/d13f662b...de327f30

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

Changes:
  - all: https://git.openjdk.org/valhalla/pull/926/files
  - new: https://git.openjdk.org/valhalla/pull/926/files/de327f30..de327f30

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=926&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=926&range=00-01

  Stats: 0 lines in 0 files changed: 0 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/valhalla/pull/926.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/926/head:pull/926

PR: https://git.openjdk.org/valhalla/pull/926