nitc: explain asserts only if Array is available, for nitcg
nitc: explain asserts only if Array is available, for nitcg

nitcg failed on base.isa.base_isa_vt_gen1.

Signed-off-by: Alexis Laferrière <b039e421609d7f6745b4f3c2461976cf9144304c@xymus.net>

privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit