Test P521-SHA512 in bogo

This makes it possible for our bogo config.json to vary
between providers.  That is achieved by -- with my sincere apologies --
applying the C preprocessor.

bogo/.gitignore

@@ -1,3 +1,4 @@
 runner.tar.gz
 testresult.tar.gz
 bogo/
+config.json

bogo/config.json.in

@@ -63,8 +63,10 @@
     "*-VerifyDefault-RSA_PKCS1_SHA1-*": "no sha1",
     "*_P224_*": "no p224",
     "*-P-224-*": "",
-    "*_P521_*": "no p521",
-    "CurveTest-Client-P-521-TLS12": "",
+#ifdef RING
+    "*-ECDSA_P521_SHA512-*": "no p521 signatures/verification",
+#endif
+    "CurveTest-Client-P-521-TLS12": "no p521 key exchange",
     "CurveTest-Server-P-521-TLS12": "",
     "CurveTest-Client-Compressed-P-521-TLS12": "",
     "CurveTest-Server-Compressed-P-521-TLS12": "",
@@ -121,6 +123,10 @@
     "Server-VerifyDefault-Ed25519-TLS12": "",
     "Client-VerifyDefault-Ed25519-TLS13": "",
     "Client-VerifyDefault-Ed25519-TLS12": "",
+    "Server-VerifyDefault-ECDSA_P521_SHA512-TLS13": "p521-sha512 accepted by default (where supported)",
+    "Server-VerifyDefault-ECDSA_P521_SHA512-TLS12": "",
+    "Client-VerifyDefault-ECDSA_P521_SHA512-TLS13": "",
+    "Client-VerifyDefault-ECDSA_P521_SHA512-TLS12": "",
     "*-HintMismatch-*": "hints are a boringssl-specific feature",
     "*-QUIC-*" :"",
     "QUIC-*": "",

bogo/runme

@@ -8,9 +8,11 @@ set -xe
 case ${BOGO_SHIM_PROVIDER:-ring} in
   ring)
       cargo build -p rustls --example bogo_shim
+      cpp -P -DRING config.json.in -oconfig.json
       ;;
   aws-lc-rs)
       cargo build -p rustls --example bogo_shim --no-default-features --features aws_lc_rs,tls12,logging
+      cpp -P -DAWS_LC_RS config.json.in -oconfig.json
       ;;
   existing)
       ;;

rustls/examples/internal/bogo_shim_impl.rs

@@ -397,6 +397,7 @@ fn lookup_scheme(scheme: u16) -> SignatureScheme {
         0x0601 => SignatureScheme::RSA_PKCS1_SHA512,
         0x0403 => SignatureScheme::ECDSA_NISTP256_SHA256,
         0x0503 => SignatureScheme::ECDSA_NISTP384_SHA384,
+        0x0603 => SignatureScheme::ECDSA_NISTP521_SHA512,
         0x0804 => SignatureScheme::RSA_PSS_SHA256,
         0x0805 => SignatureScheme::RSA_PSS_SHA384,
         0x0806 => SignatureScheme::RSA_PSS_SHA512,