RFR: 8367014: Rename class Atomic to AtomicAccess

[Andrew Haley]

On Mon, 8 Sep 2025 06:26:03 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

> 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.

`AtomicAccess` is a bit wordy, and this change is going to mess up diffs for backports terribly, but I can't think of a better way to do it. Thanks.

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Marked as reviewed by aph (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/27135#pullrequestreview-3195732355