RFR: 8310053: VarHandle and slice handle derived from layout are lacking alignment check [v5]

[Jorn Vernee]

> Add missing alignment checks for the alignment constraint of the root layout of a VarHandle created through `MemoryLayout::varHandle` and a MethodHandle `MemoryLayout::sliceHandle`.
> 
> Testing: `jdk_foreign` test suite

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

  only check alignment of root for the first deref in a chain
  minor javadoc fix
  add test for misaligned deref

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Changes:
  - all: https://git.openjdk.org/jdk/pull/14475/files
  - new: https://git.openjdk.org/jdk/pull/14475/files/99076262..b486d46e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14475&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14475&range=03-04

  Stats: 18 lines in 3 files changed: 16 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/14475.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14475/head:pull/14475

PR: https://git.openjdk.org/jdk/pull/14475