[lworld] RFR: 8298659: [lworld] ValueObject isSubstutitable comparison of float/double should use raw bits [v2]

[Roger Riggs]

> Update the substitutability implementation to match the new JLS for JEP 401.
> Float and double values should be compared for equality using the raw bits.

Roger Riggs has updated the pull request incrementally with one additional commit since the last revision:

  Revert change to ObjectMethods to avoid changing behavior of equals for floats in records.
  Create a separate cache of method pointers for substitutablity test for primitives in ValueObjectMethods.

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Changes:
  - all: https://git.openjdk.org/valhalla/pull/998/files
  - new: https://git.openjdk.org/valhalla/pull/998/files/b7a9e0f2..c951d154

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=998&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=998&range=00-01

  Stats: 42 lines in 2 files changed: 32 ins; 4 del; 6 mod
  Patch: https://git.openjdk.org/valhalla/pull/998.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/998/head:pull/998

PR: https://git.openjdk.org/valhalla/pull/998