[dev.go2go] go/go2go: update name of embedded pointer to instantiation

Fixes #39774

Change-Id: Icb2948ae19e06a3766e7edb01ef40de50e7aca7e
Reviewed-on: https://go-review.googlesource.com/c/go/+/239702
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/go/go2go/instantiate.go

@@ -819,7 +819,13 @@ func (t *translator) instantiateExpr(ta *typeArgs, e ast.Expr) ast.Expr {
 			if len(f.Names) > 0 {
 				continue
 			}
-			id, ok := f.Type.(*ast.Ident)
+			isPtr := false
+			ftyp := f.Type
+			if star, ok := ftyp.(*ast.StarExpr); ok {
+				ftyp = star.X
+				isPtr = true
+			}
+			id, ok := ftyp.(*ast.Ident)
 			if !ok {
 				continue
 			}
@@ -832,6 +838,9 @@ func (t *translator) instantiateExpr(ta *typeArgs, e ast.Expr) ast.Expr {
 				continue
 			}
 			instType := t.instantiateType(ta, typeParam)
+			if isPtr {
+				instType = types.NewPointer(instType)
+			}
 			str := types.TypeString(instType, relativeTo(t.tpkg))
 			newField := &ast.Field{
 				Doc:     f.Doc,

test/gen/g034.go2

@@ -0,0 +1,20 @@
+// compile
+
+// Copyright 2020 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.
+
+package p
+
+type I interface{}
+
+type S(type T) struct {
+	*T
+}
+
+func F() {
+	v := S(I){}
+	if v.T != nil {
+		panic(v)
+	}
+}