Mischan Toosarani-Hausberger

The macOS tests fail because AppleClang 13.0.0.13000029 seemingly ignores `-fno-optimize-sibling-calls`. However, locally with 15.0.0.15000309, the tests run successfully. I will add a corresponding `@pytest.mark.skipif` until we update our macOS runner...

> The macOS tests fail because AppleClang 13.0.0.13000029 seemingly ignores -fno-optimize-sibling-calls. However, locally with 15.0.0.15000309, the tests run successfully. I will add a corresponding @pytest.mark.skipif until we update our macOS...

This has been quite a revealing exercise. That a runtime approach to the `sigaltstack` fixed the "Old NDK"-build means that the bionic-libc implementations differ between the NDK versions (or rather...