RFR: 8314488: Compiling the JDK with C++17

[Andrew Haley]

On Thu, 26 Jun 2025 02:01:55 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

> I'm hijacking the PR mechanism as a way to discuss new C++17 features that can
> be more easily structured and captured than bare email. Once discussion
> settles down I'll turn the results into HotSpot Style Guide changes. I don't
> intend to integrate any version of this document to the OpenJDK repository.

doc/cpp17-features.md line 740:

> 738: ##### 35.1.2. Keyword `register`
> 739: 
> 740: We don't use the `register` keyword in the OpenJDK anymore?

It's essential in some uses of GCC extended asm. See `atomic_linux_aarch64.hpp` for a good example.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/25992#discussion_r2280337095