Add vendor directory and update vendorHash to null

vendor/github.com/jackc/pgx/v5/internal/pgio/write.go

@@ -0,0 +1,40 @@
+package pgio
+
+import "encoding/binary"
+
+func AppendUint16(buf []byte, n uint16) []byte {
+	wp := len(buf)
+	buf = append(buf, 0, 0)
+	binary.BigEndian.PutUint16(buf[wp:], n)
+	return buf
+}
+
+func AppendUint32(buf []byte, n uint32) []byte {
+	wp := len(buf)
+	buf = append(buf, 0, 0, 0, 0)
+	binary.BigEndian.PutUint32(buf[wp:], n)
+	return buf
+}
+
+func AppendUint64(buf []byte, n uint64) []byte {
+	wp := len(buf)
+	buf = append(buf, 0, 0, 0, 0, 0, 0, 0, 0)
+	binary.BigEndian.PutUint64(buf[wp:], n)
+	return buf
+}
+
+func AppendInt16(buf []byte, n int16) []byte {
+	return AppendUint16(buf, uint16(n))
+}
+
+func AppendInt32(buf []byte, n int32) []byte {
+	return AppendUint32(buf, uint32(n))
+}
+
+func AppendInt64(buf []byte, n int64) []byte {
+	return AppendUint64(buf, uint64(n))
+}
+
+func SetInt32(buf []byte, n int32) {
+	binary.BigEndian.PutUint32(buf, uint32(n))
+}