RFR: 8314488: Compile the JDK as C++17 [v6]

[Martin Doerr]

On Thu, 11 Jan 2024 13:23:45 GMT, Julian Waters <jwaters at openjdk.org> wrote:

>> Compile the JDK as C++17, enabling the use of all C++17 language features
>
> Julian Waters has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Require clang 13 in toolchain.m4

Thanks! We may switch to clang 14 on MacOS at some point of time, but it's better to have that disentangled. Some people build JDK 11 and 23 on the same machine and that is easier if they don't have to switch Xcode.

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Marked as reviewed by mdoerr (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/14988#pullrequestreview-1815729317