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/ssl3ext.h

@@ -98,6 +98,9 @@ struct TLSExtensionDataStr {
     /* The application token contains a value that was passed to the client via
      * a session ticket, or the cookie in a HelloRetryRequest. */
     SECItem applicationToken;
+
+    /* The record size limit set by the peer. Our value is kept in ss->opt. */
+    PRUint16 recordSizeLimit;
 };
 
 typedef struct TLSExtensionStr {