Remove useless vvp_realarray_t

The vvp_darray_real class cal be used for static arrays as well
and this is a more general solution anyhow. Kill the now useless
vvp_realarray_t class.
Runtime support for arrays of atom2 types.

This handles all of the atom integer types in unpacked arrays.
Merge branch 'master' of github.com:steveicarus/iverilog