Tests fail on aarch64 with "Cannot allocate memory"

[jpalus]

Nearly all of criterion tests fail on aarch64 with:

criterion: Could not initialize inheritable arena: Cannot allocate memory

That's because BoxFort assumes minimal address space for 64-bit hosts of 48-bit: https://github.com/Snaipe/BoxFort/blob/a26074c5cc900fabc85424253f0f64e3b9c661c3/src/arena.c#L56-L61

While on aarch64 it is possible to to have 39-bit address space see https://www.kernel.org/doc/Documentation/arm64/memory.rst