Update

vendor/golang.org/x/text/secure/bidirule/bidirule.go

@@ -334,3 +334,7 @@ func (t *Transformer) advanceString(s string) (n int, ok bool) {
 	}
 	return n, true
 }
+
+func (t *Transformer) isFinal() bool {
+	return t.state == ruleLTRFinal || t.state == ruleRTLFinal || t.state == ruleInitial
+}

vendor/golang.org/x/text/secure/bidirule/bidirule10.0.0.go

@@ -1,11 +0,0 @@
-// Copyright 2016 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.
-
-//go:build go1.10
-
-package bidirule
-
-func (t *Transformer) isFinal() bool {
-	return t.state == ruleLTRFinal || t.state == ruleRTLFinal || t.state == ruleInitial
-}

vendor/golang.org/x/text/secure/bidirule/bidirule9.0.0.go

@@ -1,14 +0,0 @@
-// Copyright 2016 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.
-
-//go:build !go1.10
-
-package bidirule
-
-func (t *Transformer) isFinal() bool {
-	if !t.isRTL() {
-		return true
-	}
-	return t.state == ruleLTRFinal || t.state == ruleRTLFinal || t.state == ruleInitial
-}