go.crypto/ssh: remove old files.

In c0fc595a2cb5, hg didn't notice the files that had been removed from
the working directory. These, old files are breaking the build.

CC=golang-codereviews
https://golang.org/cl/86240043

ssh/common_test.go

@@ -1,57 +0,0 @@
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package ssh
-
-import (
-	"io"
-	"net"
-	"testing"
-)
-
-func TestSafeString(t *testing.T) {
-	strings := map[string]string{
-		"\x20\x0d\x0a":  "\x20\x0d\x0a",
-		"flibble":       "flibble",
-		"new\x20line":   "new\x20line",
-		"123456\x07789": "123456 789",
-		"\t\t\x10\r\n":  "\t\t \r\n",
-	}
-
-	for s, expected := range strings {
-		actual := safeString(s)
-		if expected != actual {
-			t.Errorf("expected: %v, actual: %v", []byte(expected), []byte(actual))
-		}
-	}
-}
-
-// Make sure Read/Write are not exposed.
-func TestConnHideRWMethods(t *testing.T) {
-	for _, c := range []interface{}{new(ServerConn), new(ClientConn)} {
-		if _, ok := c.(io.Reader); ok {
-			t.Errorf("%T implements io.Reader", c)
-		}
-		if _, ok := c.(io.Writer); ok {
-			t.Errorf("%T implements io.Writer", c)
-		}
-	}
-}
-
-func TestConnSupportsLocalRemoteMethods(t *testing.T) {
-	type LocalAddr interface {
-		LocalAddr() net.Addr
-	}
-	type RemoteAddr interface {
-		RemoteAddr() net.Addr
-	}
-	for _, c := range []interface{}{new(ServerConn), new(ClientConn)} {
-		if _, ok := c.(LocalAddr); !ok {
-			t.Errorf("%T does not implement LocalAddr", c)
-		}
-		if _, ok := c.(RemoteAddr); !ok {
-			t.Errorf("%T does not implement RemoteAddr", c)
-		}
-	}
-}