RFR: 8343249: [Windows] Implement SpinPause [v4]

[Julian Waters]

On Mon, 2 Dec 2024 16:58:10 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> Two things:
> 
> 1. I think we need to see if there _is_ a compelling performance reason to do this. There must be `SpinPause` benchmarks somewhere.
> 2. I don't think we implement `SpinPause` for _Linux x86_, or are we?

Both Linux 32 bit and 64 bit x86 implement SpinPause in pure assembly


DECLARE_FUNC(SpinPause):
        rep
        nop
        movq   $1, %rax
        ret

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

PR Comment: https://git.openjdk.org/jdk/pull/21781#issuecomment-2535933047