Merge pull request #28340 from slavapestov/another-regression-test

Add a regression test for https://bugs.swift.org/browse/SR-10612

Author: slavapestov

validation-test/compiler_crashers_2_fixed/sr-10612.swift

@@ -0,0 +1,16 @@
+// RUN: not %target-swift-frontend -typecheck %s
+
+protocol P1: class {
+    associatedtype P1P1: P1
+    associatedtype P1AnyP2: AnyP2<P1P1>
+    
+    var anyP2: P1AnyP2? { get set }
+}
+
+protocol P2 {
+    associatedtype P2P1: P1
+}
+
+final class AnyP2<AP2P1: P1>: P2 {
+    typealias P2P1 = AP2P1
+}