runner: Make some panics more useful

Change-Id: Id53872da6c0d5bce25370f05117eb0ad642851f0
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/89408
Commit-Queue: Lily Chen <chlily@google.com>
Reviewed-by: Lily Chen <chlily@google.com>
Auto-Submit: David Benjamin <davidben@google.com>

ssl/test/runner/prf.go

diff --git a/ssl/test/runner/prf.go b/ssl/test/runner/prf.go
index 4585e46..4062a23 100644
--- a/ssl/test/runner/prf.go
+++ b/ssl/test/runner/prf.go
@@ -12,6 +12,7 @@
 	"crypto/sha1"
 	"crypto/sha256"
 	"encoding"
+	"fmt"
 	"hash"
 
 	"golang.org/x/crypto/cryptobyte"
@@ -125,7 +126,7 @@
 	case VersionTLS12:
 		return prf12(suite.hash().New)
 	}
-	panic("unknown version")
+	panic(fmt.Sprintf("unknown version 0x%x", version))
 }
 
 // masterFromPreMasterSecret generates the master secret from the pre-master
@@ -176,7 +177,7 @@
 func newFinishedHash(wireVersion uint16, isDTLS bool, cipherSuite *cipherSuite) finishedHash {
 	version, ok := wireToVersion(wireVersion, isDTLS)
 	if !ok {
-		panic("unknown version")
+		panic(fmt.Sprintf("unknown version 0x%x", wireVersion))
 	}
 
 	var ret finishedHash