This allows us to make all comparision operators on the class constexpr
without pulling in a bunch of boilerplate. We don't use the `<compare>`
header because it doesn't compile in the main serenity cross-build due
to the include paths to LibC being incompatible with how libc++ expects
them to be for clang builds.
In practice, this function does not take any perceptible amount of time.
However, this benchmark demonstrates that for extreme values, the
internal for-loop does matter.
