Support Apple Silicon natively

[axic]

While due to Rosetta fizzy will just work on macOS, it would make sense considering supporting dual-binary builds with Apple Silicon.

From https://developer.apple.com/documentation/apple_silicon/addressing_architectural_differences_in_your_macos_code:

But probably stdc++ hides this difference for us.

CMake features: https://cmake.org/cmake/help/latest/envvar/CMAKE_APPLE_SILICON_PROCESSOR.html and https://cmake.org/cmake/help/latest/variable/CMAKE_OSX_ARCHITECTURES.html

And a helpful tip (from https://cutecoder.org/software/detecting-apple-silicon-shell-script/) to force architecture selection: arch -arm64 fizzy-bench

[axic]

Technically this works, but there is still no CI run supported by CircleCI. We do have arm64 tests at least.

[axic]

From circleci:

We are now targeting end of February 2023 for our M1 launch. We thank everyone for their patience and are excited to have you try out these resources!

[axic]

Finally it is here: https://circleci.com/blog/m1-mac-resource-class/