cmd/compile: add test case for using Alias types

CL 579935 disabled usage of Alias types in the compiler, and tracks
the problem with issue #66873. The test case in #65893 passes now
with the current tip. This CL adds a test case to ensure there is no
regression once Alias types are enabled for the compiler.

Updates #66873
Fixes #65893

Change-Id: I51b51bb13ca59549bc5925dd95f73da40465556d
Reviewed-on: https://go-review.googlesource.com/c/go/+/568455
Reviewed-by: Dmitri Shuralyov <[email protected]>
Reviewed-by: Robert Griesemer <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Auto-Submit: Cuong Manh Le <[email protected]>

Author: cuonglm

test/fixedbugs/issue65893.go

@@ -0,0 +1,16 @@
+// compile
+
+// Copyright 2024 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 (
+	s  = struct{ f func(s1) }
+	s1 = struct{ i I }
+)
+
+type I interface {
+	S() *s
+}