This program successfully runs with Go 1.21:

$ cat cgo_methods.go
package main

/*
typedef int foo;
*/
import "C"

type foo = C.foo

func (foo) method() int { return 123 }

func main() {
	var x foo
	println(x.method()) // "123"
}
$ go run cgo_methods.go
123

I believe this program is invalid for the same reason as the program in #57926. Note that in contrast to that issue, this program uses an alias to define a method on a C type.