std::backtrace compatibility

[pjenvey]

Rust as of 1.65.0 (released in 2022-11) now ships with a Backtrace in std. sentry-backtrace should support its usage by providing another backtrace_to_stacktrace function that accepts a std::backtrace::Backtrace instead of backtrace::Backtrace.

[pjenvey]

It looks like one potential option for using the new std Backtrace would be to render it via e.g. format!("{:#?}", backtrace) and passing that to parse_stacktrace. Its own backtrace_to_stacktrace impl would be more efficient though.

[Swatinem]

As you mentioned, the only thing you can do with std::backtrace::Backtrace right now is Debug-format it, so I doubt it would be useful to have a separate function for it right now.

It might make sense to even completely replace the current usage of backtrace::Backtrace once the std variant is on par with it, and possibly the wider ecosystem would also move to the std variant as well, like the anyhow integration, etc.

[pjenvey]

I hadn't noticed Backtrace::frames has not stabilized yet, thanks. Agreed that that is a blocker for this.

[Swatinem]

Not only is Backtrace::frames not stabilized yet, it is also pretty useless in its current form, as the only thing you can do with it is Debug-format it.