Update NSS to 3.38

- Added HACL*Poly1305 32-bit (INRIA/Microsoft)
- Updated to final TLS 1.3 draft version (28)
- Removed TLS 1.3 prerelease draft limit check
- Removed NPN code
- Enabled dev/urandom-only RNG on Linux with NSS_SEED_ONLY_DEV_URANDOM for non-standard environments
- Fixed several bugs with TLS 1.3 negotiation
- Updated internal certificate store
- Added support for the TLS Record Size Limit Extension.
- Fixed CVE-2018-0495
- Various security fixes in the ASN.1 code.

security/nss/lib/ssl/sslspec.h

@@ -162,12 +162,18 @@ struct ssl3CipherSpecStr {
 
     DTLSEpoch epoch;
     const char *phase;
-    sslSequenceNumber seqNum;
+
+    /* The next sequence number to be sent or received. */
+    sslSequenceNumber nextSeqNum;
     DTLSRecvdRecords recvdRecords;
 
     /* The number of 0-RTT bytes that can be sent or received in TLS 1.3. This
      * will be zero for everything but 0-RTT. */
     PRUint32 earlyDataRemaining;
+    /* The maximum plaintext length.  This differs from the configured or
+     * negotiated value for TLS 1.3; it is reduced by one to account for the
+     * content type octet. */
+    PRUint16 recordSizeLimit;
 };
 
 typedef void (*sslCipherSpecChangedFunc)(void *arg,