This should help aper_put_length() to take proper decisions on the way
to encode the length, since the range alone is not enough.
A contraint of lb=1 ub=65536 would yield a range=65536, but according to
ITU-T X.691 11.9 it shouldn't be encoded using nsnnwn since that only
applies in case ub<65536.
As a result, it would end up encoding/decoding it using 2 bytes while it
should use only 1.

Related: https://github.com/mouse07410/asn1c/issues/94