RFR: 8297912: HotSpot Style Guide should permit alignas (Second Proposal Attempt) [v3]

[Julian Waters]

> [8252584](https://bugs.openjdk.org/browse/JDK-8252584) was integrated too early due to a mistake on my part, we should redo it and go through the proper approval process this time
> 
> (The changes in this commit are exactly identical to 8252584)

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

  Style

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11446/files
  - new: https://git.openjdk.org/jdk/pull/11446/files/792b96a2..33759314

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11446&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11446&range=01-02

  Stats: 12 lines in 2 files changed: 1 ins; 0 del; 11 mod
  Patch: https://git.openjdk.org/jdk/pull/11446.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11446/head:pull/11446

PR: https://git.openjdk.org/jdk/pull/11446