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

[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

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

Commit messages:
 - Fix TestLayouts on 32-bits
 - Update copyright
 - Drop unused imports in Reflection.java
 - Fix writeOversized for booleans
 - Revert changes to scopedMemoryAccess.cpp
 - Add TestUpcallStack to problem list
 - Revert changes to problem list
 - Revert to previous handshake logic
 - Initial push

Changes: https://git.openjdk.java.net/jdk/pull/7888/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7888&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8282191
  Stats: 66428 lines in 364 files changed: 44012 ins; 19911 del; 2505 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