RFR: 8282191: Implementation of Foreign Function & Memory API (Preview) [v12]

[Maurizio Cimadamore]

> This PR contains the API and implementation changes for JEP-424 [1]. A more detailed description of such changes, to avoid repetitions during the review process, is included as a separate comment.
> 
> [1] - https://openjdk.java.net/jeps/424

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 27 additional commits since the last revision:

 - Use thread local storage to optimize attach of async threads
 - Drop support for Constable from MemoryLayout/FunctionDescriptor
 - Merge branch 'master' into foreign-preview
 - Revert changes to RunTests.gmk
 - Add --enable-preview to micro benchmark java options
 - Address more review comments
 - Update src/java.base/share/classes/java/lang/foreign/SymbolLookup.java
   
   Co-authored-by: Jorn Vernee <JornVernee at users.noreply.github.com>
 - Update src/java.base/share/classes/java/lang/foreign/SymbolLookup.java
   
   Co-authored-by: Jorn Vernee <JornVernee at users.noreply.github.com>
 - Address review comments
 - Update src/java.base/share/classes/java/lang/foreign/MemorySegment.java
   
   Co-authored-by: Jorn Vernee <JornVernee at users.noreply.github.com>
 - ... and 17 more: https://git.openjdk.java.net/jdk/compare/02333d66...55aee872

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7888/files
  - new: https://git.openjdk.java.net/jdk/pull/7888/files/504b564a..55aee872

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7888&range=11
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7888&range=10-11

  Stats: 99257 lines in 1550 files changed: 79659 ins; 15544 del; 4054 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7888.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7888/head:pull/7888

PR: https://git.openjdk.java.net/jdk/pull/7888