RFR: 8305341: Alignment should be enforced by alignas instead of compiler specific attributes [v2]

[Julian Waters]

> C11 has been stable for a long time on all platforms, so native code can use the standard alignas operator for alignment requirements

Julian Waters 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 ten additional commits since the last revision:

 - gcc offset_of
 - Remove Visual C++ alignment
 - Remove gcc alignment
 - globalDefinitions.hpp
 - Merge branch 'openjdk:master' into patch-6
 - <stdalign.h>
 - GSSLibStub.c
 - ArrayReferenceImpl.c
 - Alignment outside of HotSpot should be enforced by alignas instead of compiler specific attributes

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13258/files
  - new: https://git.openjdk.org/jdk/pull/13258/files/7e5e6449..7dc7f7d8

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13258&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13258&range=00-01

  Stats: 16524 lines in 394 files changed: 7231 ins; 8051 del; 1242 mod
  Patch: https://git.openjdk.org/jdk/pull/13258.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13258/head:pull/13258

PR: https://git.openjdk.org/jdk/pull/13258