This is generated from olv/venus-protocol!17.
(fooCount, pFoo) array, we encode
fooCount twice. Previously, we
used one for allocation and the other for initialization. When the two
differed, we could allocate an array of N elements but initialize only
the first M elements. We only validated that M <= N.
After this commit,
vn_decode_array_size validates that M == N.
The other main change is that this commit adds
make sure strings are null-terminated.