RFR: 8311630: [s390] Implementation of Foreign Function & Memory API (Preview) [v6]

[sid8606]

> Implementation of "Foreign Function & Memory API" for s390x (Big Endian).

sid8606 has updated the pull request incrementally with one additional commit since the last revision:

  Preserve and restore register Z_R6
  
  Though Z_R6 is argument register it is a saved register
  so preserve and restore Z_R6 register

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Changes:
  - all: https://git.openjdk.org/jdk/pull/14801/files
  - new: https://git.openjdk.org/jdk/pull/14801/files/107b971f..cc2292dd

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14801&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14801&range=04-05

  Stats: 13 lines in 2 files changed: 3 ins; 0 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/14801.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14801/head:pull/14801

PR: https://git.openjdk.org/jdk/pull/14801