[jdk17] RFR: 8269096: Add java.util.Objects.newIdentity method

[Roger Riggs]

Add java.util.Objects.newIdentity to supply a unique object with identity.
This is a replacement code can be used today for the traditional new Object() idiom, which will be deprecated under Project Valhalla.
Refer to [JEP 401: Primitive Objects (Preview)](https://openjdk.java.net/jeps/401) for background.

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Commit messages:
 - Copyright update and cleanup punctuation
 - 8269096: Add java.util.Objects.newIdentity method

Changes: https://git.openjdk.java.net/jdk17/pull/112/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17&pr=112&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8269096
  Stats: 29 lines in 2 files changed: 28 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk17/pull/112.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17 pull/112/head:pull/112

PR: https://git.openjdk.java.net/jdk17/pull/112