RFR: 8297967: Make frame::safe_for_sender safer [v4]

[Martin Doerr]

On Tue, 6 Dec 2022 14:05:46 GMT, Johannes Bechberger <duke at openjdk.org> wrote:

>> Makes frame::safe_for_sender safer by using os::is_readable_pointer to check the location of the return address.
>
> Johannes Bechberger has updated the pull request incrementally with one additional commit since the last revision:
> 
>   More SafeFetch

Quite a few SafeFetch checks! But it's only used for profiling purposes, so checking a bit more sounds ok to me. Let's hear what other people think.
Please update the description and the JBS issue according to your new version and describe how broken values may reach this function.

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PR: https://git.openjdk.org/jdk/pull/11461