test: add test for issue 58345

CL 458619 fixed the problem un-intentionally, so adding test to prevent
regression happening.

Updates #58345

Change-Id: I80cf60716ef85e142d769e8621fce19c826be03d
Reviewed-on: https://go-review.googlesource.com/c/go/+/465455
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>

test/fixedbugs/issue58345.go

@@ -0,0 +1,15 @@
+// compile
+
+// Copyright 2023 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 I1 interface {
+	int | any
+}
+
+type I2 interface {
+	int | any
+}