Add SNI support to redbean and improve SSL perf

This change makes SSL virtual hosting possible. You can now load
multiple certificates for multiple domains and redbean will just
figure out which one to use, even if you only have 1 ip address.
You can also use a jumbo certificate that lists all your domains
in the the subject alternative names.

This change also makes performance improvements to MbedTLS. Here
are some benchmarks vs. cc1920749e

                                   BEFORE    AFTER   (microsecs)
suite_ssl.com                     2512881   191738 13.11x faster
suite_pkparse.com                   36291     3295 11.01x faster
suite_x509parse.com                854669   120293  7.10x faster
suite_pkwrite.com                    6549     1265  5.18x faster
suite_ecdsa.com                     53347    18778  2.84x faster
suite_pk.com                        49051    18717  2.62x faster
suite_ecdh.com                      19535     9502  2.06x faster
suite_shax.com                      15848     7965  1.99x faster
suite_rsa.com                      353257   184828  1.91x faster
suite_x509write.com                162646    85733  1.90x faster
suite_ecp.com                       20503    11050  1.86x faster
suite_hmac_drbg.no_reseed.com       19528    11417  1.71x faster
suite_hmac_drbg.nopr.com            12460     8010  1.56x faster
suite_mpi.com                      687124   442661  1.55x faster
suite_hmac_drbg.pr.com              11890     7752  1.53x faster

There aren't any special tricks to the performance imporvements.
It's mostly due to code cleanup, assembly and intel instructions
like mulx, adox, and adcx.

third_party/mbedtls/config.h

@@ -1,5 +1,6 @@
 #ifndef MBEDTLS_CONFIG_H_
 #define MBEDTLS_CONFIG_H_
+#include "libc/dce.h"
 
 /* protocols */
 #define MBEDTLS_SSL_PROTO_TLS1_2
@@ -46,8 +47,8 @@
 /* block modes */
 #define MBEDTLS_GCM_C
 #ifndef TINY
-/*#define MBEDTLS_CCM_C*/
 #define MBEDTLS_CIPHER_MODE_CBC
+/*#define MBEDTLS_CCM_C*/
 /*#define MBEDTLS_CIPHER_MODE_CFB*/
 /*#define MBEDTLS_CIPHER_MODE_CTR*/
 /*#define MBEDTLS_CIPHER_MODE_OFB*/
@@ -60,9 +61,9 @@
 #ifndef TINY
 #define MBEDTLS_ECP_C
 #define MBEDTLS_ECDH_C
-#define MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED
 #define MBEDTLS_ECDSA_C
 #define MBEDTLS_ECDSA_DETERMINISTIC
+#define MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED
 #define MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED
 #define MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED
 /*#define MBEDTLS_DHM_C*/
@@ -113,7 +114,7 @@
 #endif
 #endif
 
-#ifndef NDEBUG
+#if IsModeDbg()
 #define MBEDTLS_CHECK_PARAMS
 #endif
 
@@ -121,11 +122,10 @@
 #define MBEDTLS_SHA1_SMALLER
 #define MBEDTLS_SHA256_SMALLER
 #define MBEDTLS_SHA512_SMALLER
+#define MBEDTLS_ECP_NIST_OPTIM
 #ifdef TINY
 #define MBEDTLS_AES_ROM_TABLES
 #define MBEDTLS_AES_FEWER_TABLES
-#else
-#define MBEDTLS_ECP_NIST_OPTIM
 #endif
 
 #define MBEDTLS_PLATFORM_C
@@ -793,7 +793,7 @@
  *
  * Comment this macro to disable support for server name indication in SSL
  */
-/*#define MBEDTLS_SSL_SERVER_NAME_INDICATION*/
+#define MBEDTLS_SSL_SERVER_NAME_INDICATION
 
 /**
  * \def MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH
@@ -1205,7 +1205,6 @@
  * \warning   SHA-1 is considered a weak message digest and its use constitutes
  *            a security risk. If possible, we recommend avoiding dependencies
  *            on it, and considering stronger message digests instead.
- *
  */
 /*#define MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES*/
 
@@ -1223,7 +1222,11 @@
  *            a security risk. If possible, we recommend avoiding dependencies
  *            on it, and considering stronger message digests instead.
  */
-/*#define MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_KEY_EXCHANGE*/
+#define MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_KEY_EXCHANGE
 
+#define mbedtls_t_udbl uint128_t
+#define MBEDTLS_HAVE_UDBL
+
+#include "libc/dce.h"
 #include "third_party/mbedtls/check.h"
 #endif /* MBEDTLS_CONFIG_H_ */