[lworld] RFR: [lworld] Various fixes [v2]

[Frederic Parain]

> Bag of various fixes:
>   - removal of dead code
>   - cleanup of existing code (simplification, removal of repeated actions)
>   - refactoring some code to make it more readable
>   - some adjustments because of abstract value classes
>   - some minor fixes
> 
> 
> Fred

Frederic Parain 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 three additional commits since the last revision:

 - Merge remote-tracking branch 'upstream/lworld' into code_cleanup
 - Fix typos
 - Code cleanup and adjustments to abstract value classes

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

Changes:
  - all: https://git.openjdk.org/valhalla/pull/1140/files
  - new: https://git.openjdk.org/valhalla/pull/1140/files/d7f0e1f6..8fabaaee

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1140&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1140&range=00-01

  Stats: 2745 lines in 93 files changed: 594 ins; 2060 del; 91 mod
  Patch: https://git.openjdk.org/valhalla/pull/1140.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1140/head:pull/1140

PR: https://git.openjdk.org/valhalla/pull/1140