Ensure that the SILK encoder's log gain is 63, not 64, when encoding
a maximum-value delta gain index of 40. This matches the decoder
and RFC 6716 4.2.7.4, and prevents an assertion failure in the rare
case that the gain is later independently coded.
Fix Hybrid redundancy assertion failure in ec_enc_shrink(), even
if SILK produces more than maxBits, by reducing or eliminating
redundancy when necessary. Don't reserve space for redundancy that
is too small to be used for redundancy. When there is not enough
space for redundancy, allow the regular frame to use all the bits.
