tpl: Sync go_templates for Go 1.18

Using Go tag go1.18 4aa1efed4853ea067d665a952eee77c52faac774

Updates #9677

tpl/internal/go_templates/texttemplate/parse/lex_test.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.13
 // +build go1.13
 
 package parse
@@ -37,6 +38,8 @@ var itemName = map[itemType]string{
 	// keywords
 	itemDot:      ".",
 	itemBlock:    "block",
+	itemBreak:    "break",
+	itemContinue: "continue",
 	itemDefine:   "define",
 	itemElse:     "else",
 	itemIf:       "if",