RFR: JDK-8286666: JEP 429: Implementation of Scoped Values (Incubator) [v3]

[Andrew Haley]

> JEP 429 implementation.

Andrew Haley has updated the pull request incrementally with one additional commit since the last revision:

  Reviewer feedback

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Changes:
  - all: https://git.openjdk.org/jdk/pull/10952/files
  - new: https://git.openjdk.org/jdk/pull/10952/files/4bd44d66..442a04ef

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10952&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10952&range=01-02

  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/10952.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10952/head:pull/10952

PR: https://git.openjdk.org/jdk/pull/10952