[jdk17u-dev] RFR: 8273459: Update code segment alignment to 64 bytes

[Scott Gibbons]

One of 3 dependent backports for Base64 that are required to get the real bugfix cleanly integrated.  The next one will be for align32(), then followed by the buffer overrun bugfix required for Base64 decoding to work properly.

Risk: I view the risk of this backport to be minimal. This code has been in use for many months with no bugs reported.

Testing: x86_64 build, affected tests, tier1

Thanks,
--Scott

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

Depends on: https://git.openjdk.org/jdk17u-dev/pull/861

Commit messages:
 - Backport 53b25bce878bc291f3a217da7c26fd3097f18cfd

Changes: https://git.openjdk.org/jdk17u-dev/pull/862/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=862&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8273459
  Stats: 27 lines in 4 files changed: 10 ins; 0 del; 17 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/862.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev pull/862/head:pull/862

PR: https://git.openjdk.org/jdk17u-dev/pull/862