RFR: 8295044: Implementation of Foreign Function and Memory API (Second Preview) [v10]

[Maurizio Cimadamore]

> This PR contains the API and implementation changes for JEP-434 [1]. A more detailed description of such changes, to avoid repetitions during the review process, is included as a separate comment.
> 
> [1] - https://openjdk.org/jeps/434

Maurizio Cimadamore has updated the pull request incrementally with two additional commits since the last revision:

 - Revamp javadoc of Arena/MemorySession
   Rename MemorySession::isOwnedBy to MemorySession::isAccessibleBy
   Add Arena::isOwnedBy
 - Javadoc tweaks in MemorySession/Arena

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Changes:
  - all: https://git.openjdk.org/jdk/pull/10872/files
  - new: https://git.openjdk.org/jdk/pull/10872/files/e2840232..fd367106

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10872&range=09
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10872&range=08-09

  Stats: 311 lines in 10 files changed: 63 ins; 28 del; 220 mod
  Patch: https://git.openjdk.org/jdk/pull/10872.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10872/head:pull/10872

PR: https://git.openjdk.org/jdk/pull/10872