Add failing test case for GSB bug

Author: slavapestov

validation-test/compiler_crashers_2/0189-sr10033.swift

@@ -0,0 +1,20 @@
+// RUN: not --crash %target-swift-frontend -typecheck %s
+
+protocol P1 {
+  associatedtype A2 : P2 where A2.A1 == Self
+}
+
+protocol P2 {
+  associatedtype A1 : P1 where A1.A2 == Self
+  var property: Int { get }
+}
+
+extension P2 {
+  var property: Int { return 0 }
+}
+
+class C1 : P1 {
+  class A2 : P2 {
+    typealias A1 = C1
+  }
+}