[AlignedNumber] Run the SIMD testsuite.
Also run the simd testsuite on AlignedNumber, sind it does provide a SIMD abstraction.
Also fixes one issue with that abstraction (though I do not recall why exactly
I did not allow const Scalar<T> &lane(T &&)
, but required the return type to
be one of Scalar<T>
or Scalar<T>&&
).
Closes: #123 (closed).