Fix check for the availability of std::bit_cast

[TobiSchluter]

Checking for the language version is not going to help for incomplete libraries such as on Apple or Android. This fixes this by using the bit_cast-specific macro.

[linux-foundation-easycla]

• ❌ - login: @TobiSchluter / name: Tobias Schlüter . The commit (acf2f1e) is not authorized under a signed CLA. Please click here to be authorized. For further assistance with EasyCLA, please submit a support request ticket.

[TobiSchluter]

I don't believe that a change this small can be covered by copyright.

[meshula]

Found the docs here ~ https://en.cppreference.com/w/cpp/feature_test ~ everything looks correct to me.

Filling out the CLA is straight forward, however if you're not interested in doing it for such a small change, we can go ahead and make the change ourselves.

[TobiSchluter]

Thank you. I spent the same amount it took me to look up the relevant macro name and write the patch trying to find the text of the CLA and failed. I'm sure that I can find it if I look for another 30 seconds :) The patch itself certainly fails all criteria for copyrightability even in the most ownership-friendly jurisdictions. So, I don't think it's a worthy pursuit for me to read and sign the CLA and I'm grateful that you offered to come up with the (likely identical) change yourself.

[cary-ilm]

Closing in favor of #350

[TobiSchluter]

Thank you!