reflect: add pointerTo()

src/reflect/type.go

@@ -452,13 +452,19 @@ func TypeOf(i interface{}) Type {
 func PtrTo(t Type) Type { return PointerTo(t) }
 
 func PointerTo(t Type) Type {
+	return pointerTo(t.(*rawType))
+}
+
+func pointerTo(t *rawType) *rawType {
 	switch t.Kind() {
 	case Pointer:
+		// TODO(dgryski): This is blocking https://github.com/tinygo-org/tinygo/issues/3131
+		// We need to be able to create types that match existing types to prevent typecode equality.
 		panic("reflect: cannot make **T type")
 	case Struct:
-		return (*structType)(unsafe.Pointer(t.(*rawType))).ptrTo
+		return (*structType)(unsafe.Pointer(t)).ptrTo
 	default:
-		return (*elemType)(unsafe.Pointer(t.(*rawType))).ptrTo
+		return (*elemType)(unsafe.Pointer(t)).ptrTo
 	}
 }
 

src/reflect/value.go

@@ -1017,7 +1017,7 @@ func Zero(typ Type) Value {
 // new value of the given type.
 func New(typ Type) Value {
 	return Value{
-		typecode: PtrTo(typ).(*rawType),
+		typecode: pointerTo(typ.(*rawType)),
 		value:    alloc(typ.Size(), nil),
 		flags:    valueFlagExported,
 	}