update to latest dependencies

vendor/golang.org/x/mod/modfile/work.go

@@ -12,9 +12,10 @@ import (
 
 // A WorkFile is the parsed, interpreted form of a go.work file.
 type WorkFile struct {
-	Go      *Go
-	Use     []*Use
-	Replace []*Replace
+	Go        *Go
+	Toolchain *Toolchain
+	Use       []*Use
+	Replace   []*Replace
 
 	Syntax *FileSyntax
 }
@@ -109,7 +110,7 @@ func (f *WorkFile) Cleanup() {
 
 func (f *WorkFile) AddGoStmt(version string) error {
 	if !GoVersionRE.MatchString(version) {
-		return fmt.Errorf("invalid language version string %q", version)
+		return fmt.Errorf("invalid language version %q", version)
 	}
 	if f.Go == nil {
 		stmt := &Line{Token: []string{"go", version}}
@@ -117,7 +118,7 @@ func (f *WorkFile) AddGoStmt(version string) error {
 			Version: version,
 			Syntax:  stmt,
 		}
-		// Find the first non-comment-only block that's and add
+		// Find the first non-comment-only block and add
 		// the go statement before it. That will keep file comments at the top.
 		i := 0
 		for i = 0; i < len(f.Syntax.Stmt); i++ {
@@ -133,6 +134,56 @@ func (f *WorkFile) AddGoStmt(version string) error {
 	return nil
 }
 
+func (f *WorkFile) AddToolchainStmt(name string) error {
+	if !ToolchainRE.MatchString(name) {
+		return fmt.Errorf("invalid toolchain name %q", name)
+	}
+	if f.Toolchain == nil {
+		stmt := &Line{Token: []string{"toolchain", name}}
+		f.Toolchain = &Toolchain{
+			Name:   name,
+			Syntax: stmt,
+		}
+		// Find the go line and add the toolchain line after it.
+		// Or else find the first non-comment-only block and add
+		// the toolchain line before it. That will keep file comments at the top.
+		i := 0
+		for i = 0; i < len(f.Syntax.Stmt); i++ {
+			if line, ok := f.Syntax.Stmt[i].(*Line); ok && len(line.Token) > 0 && line.Token[0] == "go" {
+				i++
+				goto Found
+			}
+		}
+		for i = 0; i < len(f.Syntax.Stmt); i++ {
+			if _, ok := f.Syntax.Stmt[i].(*CommentBlock); !ok {
+				break
+			}
+		}
+	Found:
+		f.Syntax.Stmt = append(append(f.Syntax.Stmt[:i:i], stmt), f.Syntax.Stmt[i:]...)
+	} else {
+		f.Toolchain.Name = name
+		f.Syntax.updateLine(f.Toolchain.Syntax, "toolchain", name)
+	}
+	return nil
+}
+
+// DropGoStmt deletes the go statement from the file.
+func (f *WorkFile) DropGoStmt() {
+	if f.Go != nil {
+		f.Go.Syntax.markRemoved()
+		f.Go = nil
+	}
+}
+
+// DropToolchainStmt deletes the toolchain statement from the file.
+func (f *WorkFile) DropToolchainStmt() {
+	if f.Toolchain != nil {
+		f.Toolchain.Syntax.markRemoved()
+		f.Toolchain = nil
+	}
+}
+
 func (f *WorkFile) AddUse(diskPath, modulePath string) error {
 	need := true
 	for _, d := range f.Use {