dl: add go1.17

Change-Id: If8e4e29dea893eaaeb84aa144c56966db4f53e71
Reviewed-on: https://go-review.googlesource.com/c/dl/+/342484
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Trust: Michael Knyszek <mknyszek@google.com>

go1.17/main.go

@@ -0,0 +1,24 @@
+// Copyright 2021 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.
+
+// The go1.17 command runs the go command from Go 1.17.
+//
+// To install, run:
+//
+//     $ go install golang.org/dl/go1.17@latest
+//     $ go1.17 download
+//
+// And then use the go1.17 command as if it were your normal go
+// command.
+//
+// See the release notes at https://golang.org/doc/go1.17
+//
+// File bugs at https://golang.org/issues/new
+package main
+
+import "golang.org/dl/internal/version"
+
+func main() {
+	version.Run("go1.17")
+}