crypto/evp: harden AEAD ciphers.

Originally a crash in 32-bit build was reported CHACHA20-POLY1305
cipher. The crash is triggered by truncated packet and is result
of excessive hashing to the edge of accessible memory. Since hash
operation is read-only it is not considered to be exploitable
beyond a DoS condition. Other ciphers were hardened.

Thanks to Robert Święcki for report.

CVE-2017-3731

Reviewed-by: Rich Salz <rsalz@openssl.org>
const EVP_CIPHER *EVP_aes_128_wrap(void)
{
    return &aes_128_wrap;
}

const EVP_CIPHER *EVP_aes_128_wrap(void)
{
    return &aes_128_wrap;
}
