[lworld] RFR: 8375319: [lworld] System.identityHashCode wrong for Wrapper classes with -XX:+UseAltSubstitutabilityMethod [v2]

[Roger Riggs]

> For all value classes, including the wrapper classes,  seed the AltHashCode implementation on the SALT value.

Roger Riggs 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:

 - Re-enable the Alt hashcode implementation to be used with -XX:+UseAltSubstitutabilityMethod
 - Merge branch 'lworld' into 8375319-hashcode-add-salt
 - 8375319: [lworld] System.identityHashCode wrong for Wrapper classes with -XX:+UseAltSubstitutabilityMethod
   Seed the AltHashCode implementation on the SALT value.

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

Changes:
  - all: https://git.openjdk.org/valhalla/pull/1924/files
  - new: https://git.openjdk.org/valhalla/pull/1924/files/57bdfebd..4beb1006

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1924&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1924&range=00-01

  Stats: 1938 lines in 19 files changed: 99 ins; 1762 del; 77 mod
  Patch: https://git.openjdk.org/valhalla/pull/1924.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1924/head:pull/1924

PR: https://git.openjdk.org/valhalla/pull/1924