o implement add1() using 32 bit ints, this makes _krb5_n_fold()
about 5% faster on an amd64 platform. 64 bit ints yield a
further improvement but we would need to test the platform
to see if they are natively supported. This should yield
better performance improvements on big endian machines as
we have to byte swap on little endian boxen.
o fix two cases where a malloc(3)d pointer may be dereferenced
before we test that it is not NULL.
66f4c441e9