[foreign-memaccess] [Rev 03] RFR: JDK-8243073: Add support for serial confinement

[Maurizio Cimadamore]

> This patch adds support for serial confinement - e.g. a handoff operation to transfer ownership from thread A to thread
> B.
> The implementation is based on some iterations we have done in the past. I've added a test, and I've also rewritten
> some of the existing tests not to rely on waits, but to use latches instead, as observed by Paul.

Maurizio Cimadamore has updated the pull request with a new target base due to a merge or a rebase. The incremental
webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits
since the last revision:

 - Add hyperlink to "happens before" definition.
 - Clarify javadoc after discussions with Doug and Paul
 - Added more documentation about safety guarantees of the new handoff operation
   Moved full fence after instance creation
 - * Add support for withOwnerThread operation
   * added test
   * rewritten negative shared tests with pending acquired views to use latches instead of waits

-------------

Changes:
  - all: https://git.openjdk.java.net/panama-foreign/pull/117/files
  - new: https://git.openjdk.java.net/panama-foreign/pull/117/files/3f620959..36f67619

Webrevs:
 - full: https://webrevs.openjdk.java.net/panama-foreign/117/webrev.03
 - incr: https://webrevs.openjdk.java.net/panama-foreign/117/webrev.02-03

  Stats: 840054 lines in 4183 files changed: 5022 ins; 832624 del; 2408 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/117.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/117/head:pull/117

PR: https://git.openjdk.java.net/panama-foreign/pull/117