RFR: 8367014: Rename class Atomic to AtomicAccess

[Kim Barrett]

Please review this change that renames the all-static class `Atomic` to
`AtomicAccess`. The reason for this name change is to allow the introduction
of the new type `Atomic<T>` ([JDK-8367013](https://bugs.openjdk.org/browse/JDK-8367013)).

The PR has several commits, according to the specific category of change being
made. It may be easier to review the PR by studying these individual commits.

Although the file "atomic.hpp" is being renamed to "atomicAccess.hpp", I chose
to not rename the various "atomic_<cpu>.*" and "atomic_<os>_<cpu>.*" files.

There are a number of comments containing the word "Atomic" that I didn't
change. They are generically about atomic operations, and will just as well
serve as referring to the future `Atomic<T>`.

Testing: mach5 tier1, GHA sanity tests.
This is one of those changes where successful builds indicate the change is good.

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

Commit messages:
 - update copyrights
 - misc cleanups
 - fix indentation from rename
 - rename Atomic => AtomicAccess in gtests
 - rename Atomic => AtomicAccess
 - change includes of atomic.hpp in gtests
 - change includes of atomic.hpp
 - rename atomic.hpp => atomicAccess.hpp

Changes: https://git.openjdk.org/jdk/pull/27135/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27135&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8367014
  Stats: 4894 lines in 427 files changed: 1237 ins; 1235 del; 2422 mod
  Patch: https://git.openjdk.org/jdk/pull/27135.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27135/head:pull/27135

PR: https://git.openjdk.org/jdk/pull/27135