[lworld] RFR: 8366841 objects equals no acmp

[Roger Riggs]

Modify java.util.Objects.equals to avoid acmp (==) when --enable-preview.

There is a simple bug fix in the SimpleValueGraphs test.

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Commit messages:
 - Merge branch 'lworld' into 8366841-objects-equals-no-acmp
 - Bug fix in SimpleValueGraphs.SimpleValue.equals; compare corresponding fields
 - 8366841: [lworld] Objects.equals without identity comparison

Changes: https://git.openjdk.org/valhalla/pull/1551/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1551&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8366841
  Stats: 9 lines in 2 files changed: 6 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/valhalla/pull/1551.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1551/head:pull/1551

PR: https://git.openjdk.org/valhalla/pull/1551