tpl: Sync go_templates for Go 1.18

Using Go tag go1.18 4aa1efed4853ea067d665a952eee77c52faac774

Updates #9677

tpl/internal/go_templates/htmltemplate/context.go

@@ -4,7 +4,11 @@
 
 package template
 
-import "fmt"
+import (
+	"fmt"
+
+	"github.com/gohugoio/hugo/tpl/internal/go_templates/texttemplate/parse"
+)
 
 // context describes the state an HTML parser must be in when it reaches the
 // portion of HTML produced by evaluating a particular template node.
@@ -20,6 +24,7 @@ type context struct {
 	jsCtx   jsCtx
 	attr    attr
 	element element
+	n       parse.Node // for range break/continue
 	err     *Error
 }
 
@@ -139,6 +144,8 @@ const (
 	// stateError is an infectious error state outside any valid
 	// HTML/CSS/JS construct.
 	stateError
+	// stateDead marks unreachable code after a {{break}} or {{continue}}.
+	stateDead
 )
 
 // isComment is true for any state that contains content meant for template