remove unused definitions on messages.go

messages.go

@@ -3,16 +3,9 @@ package pgx
 import (
 	"database/sql/driver"
 
-	"github.com/jackc/pgio"
 	"github.com/jackc/pgtype"
 )
 
-const (
-	copyData = 'd'
-	copyFail = 'f'
-	copyDone = 'c'
-)
-
 func convertDriverValuers(args []interface{}) ([]interface{}, error) {
 	for i, arg := range args {
 		switch arg := arg.(type) {
@@ -28,15 +21,3 @@ func convertDriverValuers(args []interface{}) ([]interface{}, error) {
 	}
 	return args, nil
 }
-
-// appendQuery appends a PostgreSQL wire protocol query message to buf and returns it.
-func appendQuery(buf []byte, query string) []byte {
-	buf = append(buf, 'Q')
-	sp := len(buf)
-	buf = pgio.AppendInt32(buf, -1)
-	buf = append(buf, query...)
-	buf = append(buf, 0)
-	pgio.SetInt32(buf[sp:], int32(len(buf[sp:])))
-
-	return buf
-}