RFR: 8369468: Rdtsc: Move getCPUIDBrandString_stub into VM_Version stub area

[Axel Boldt-Christmas]

On Thu, 9 Oct 2025 05:59:54 GMT, Axel Boldt-Christmas <aboldtch at openjdk.org> wrote:

> Currently these stubs are created in `Rdtsc::initialize` which may be called from the first ElapsedCounter now call. This causes problems with lock ranks as we may be holding a lock while taking time, because we need to lock the code cache to create a stub.
> 
> I suggest we move the `getCPUIDBrandString_stub` next to the other `VM_Version` stubs and generate them together. This is done at the earliest point we can, right after the CodeCache system has been initialized.

Thanks for the reviews

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PR Comment: https://git.openjdk.org/jdk/pull/27711#issuecomment-3396269806