godoc/static: have makestatic use the same code header comment as stringer

This allows Github to hide diffs in generated files. See:
https://github.com/github/linguist/blob/473282d/lib/linguist/generated.rb#L241

Change-Id: I0565c729dacfa7861e7da7eb66bc8021d191fc3e
Reviewed-on: https://go-review.googlesource.com/15074
Reviewed-by: Andrew Gerrand <adg@golang.org>

godoc/static/makestatic.go

@@ -84,7 +84,7 @@ func makestatic() error {
 	}
 	defer f.Close()
 	w := bufio.NewWriter(f)
-	fmt.Fprintf(w, "%v\n\npackage static\n\n", warning)
+	fmt.Fprintf(w, "%v\npackage static\n\n", warning)
 	fmt.Fprintf(w, "var Files = map[string]string{\n")
 	for _, fn := range files {
 		b, err := ioutil.ReadFile(fn)
@@ -118,4 +118,4 @@ func sanitize(b []byte) []byte {
 	return bytes.Replace(b, []byte("\xEF\xBB\xBF"), []byte("`+\"\\xEF\\xBB\\xBF\"+`"), -1)
 }
 
-const warning = "// DO NOT EDIT ** This file was generated by \"go generate\" ** DO NOT EDIT //"
+const warning = "// Code generated by \"makestatic\"; DO NOT EDIT\n"

godoc/static/static.go

@@ -1,4 +1,4 @@
-// DO NOT EDIT ** This file was generated by "go generate" ** DO NOT EDIT //
+// Code generated by "makestatic"; DO NOT EDIT
 
 package static