diff --git a/src/cmd/cgo/ast.go b/src/cmd/cgo/ast.go
index 861479db7ac..97b18cd22d4 100644
--- a/src/cmd/cgo/ast.go
+++ b/src/cmd/cgo/ast.go
@@ -363,7 +363,8 @@ func (f *File) walk(x interface{}, context astContext, visit func(*File, interfa
 
 	// everything else just recurs
 	default:
-		f.walkUnexpected(x, context, visit)
+		error_(token.NoPos, "unexpected type %T in walk", x)
+		panic("unexpected type")
 
 	case nil:
 
@@ -396,6 +397,9 @@ func (f *File) walk(x interface{}, context astContext, visit func(*File, interfa
 	case *ast.IndexExpr:
 		f.walk(&n.X, ctxExpr, visit)
 		f.walk(&n.Index, ctxExpr, visit)
+	case *ast.IndexListExpr:
+		f.walk(&n.X, ctxExpr, visit)
+		f.walk(n.Indices, ctxExpr, visit)
 	case *ast.SliceExpr:
 		f.walk(&n.X, ctxExpr, visit)
 		if n.Low != nil {
@@ -434,8 +438,8 @@ func (f *File) walk(x interface{}, context astContext, visit func(*File, interfa
 	case *ast.StructType:
 		f.walk(n.Fields, ctxField, visit)
 	case *ast.FuncType:
-		if tparams := funcTypeTypeParams(n); tparams != nil {
-			f.walk(tparams, ctxParam, visit)
+		if n.TypeParams != nil {
+			f.walk(n.TypeParams, ctxParam, visit)
 		}
 		f.walk(n.Params, ctxParam, visit)
 		if n.Results != nil {
@@ -524,8 +528,8 @@ func (f *File) walk(x interface{}, context astContext, visit func(*File, interfa
 			f.walk(n.Values, ctxExpr, visit)
 		}
 	case *ast.TypeSpec:
-		if tparams := typeSpecTypeParams(n); tparams != nil {
-			f.walk(tparams, ctxParam, visit)
+		if n.TypeParams != nil {
+			f.walk(n.TypeParams, ctxParam, visit)
 		}
 		f.walk(&n.Type, ctxType, visit)
 
diff --git a/src/cmd/cgo/ast_go1.go b/src/cmd/cgo/ast_go1.go
deleted file mode 100644
index 2f65f0f7183..00000000000
--- a/src/cmd/cgo/ast_go1.go
+++ /dev/null
@@ -1,25 +0,0 @@
-// Copyright 2021 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 compiler_bootstrap
-
-package main
-
-import (
-	"go/ast"
-	"go/token"
-)
-
-func (f *File) walkUnexpected(x interface{}, context astContext, visit func(*File, interface{}, astContext)) {
-	error_(token.NoPos, "unexpected type %T in walk", x)
-	panic("unexpected type")
-}
-
-func funcTypeTypeParams(n *ast.FuncType) *ast.FieldList {
-	return nil
-}
-
-func typeSpecTypeParams(n *ast.TypeSpec) *ast.FieldList {
-	return nil
-}
diff --git a/src/cmd/cgo/ast_go118.go b/src/cmd/cgo/ast_go118.go
deleted file mode 100644
index ced30728dc9..00000000000
--- a/src/cmd/cgo/ast_go118.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Copyright 2021 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 !compiler_bootstrap
-
-package main
-
-import (
-	"go/ast"
-	"go/token"
-)
-
-func (f *File) walkUnexpected(x interface{}, context astContext, visit func(*File, interface{}, astContext)) {
-	switch n := x.(type) {
-	default:
-		error_(token.NoPos, "unexpected type %T in walk", x)
-		panic("unexpected type")
-
-	case *ast.IndexListExpr:
-		f.walk(&n.X, ctxExpr, visit)
-		f.walk(n.Indices, ctxExpr, visit)
-	}
-}
-
-func funcTypeTypeParams(n *ast.FuncType) *ast.FieldList {
-	return n.TypeParams
-}
-
-func typeSpecTypeParams(n *ast.TypeSpec) *ast.FieldList {
-	return n.TypeParams
-}