RFR: 8254275: [valhalla/jep390] Revise "value-based class" & apply to wrappers [v8]

[Dan Smith]

> Polishing the specification of "value-based class" to align with requirements of inline classes, allow classes (like Integer) with deprecated constructors, and clarify expectations for clients.
> 
> Full docs build: http://cr.openjdk.java.net/~dlsmith/8254275/8254275-20201013/api/index.html

Dan Smith has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains eight commits:

 - Merge branch 'jep390' into 8254275
 - Merge branch 'jep390' into 8254275
 - Don't claim ConstantDescs or DynamicCallSiteDescs are value-based
 - Review comments
 - Addressing additional review comments for ValueBased.html
 - Addressing review comments in ValueBased.html
 - Revise definition for more flexible ==. Apply revised boilerplate to wrappers and existing references.
 - 8254275: Development to revise ValueBased.html for consistency with inline class migration

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Changes: https://git.openjdk.java.net/valhalla/pull/222/files
 Webrev: https://webrevs.openjdk.java.net/?repo=valhalla&pr=222&range=07
  Stats: 258 lines in 48 files changed: 60 ins; 20 del; 178 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/222.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/222/head:pull/222

PR: https://git.openjdk.java.net/valhalla/pull/222