Add regression test for rdar://30832766, fixed by AnyObject removal

Author: slavapestov

test/ClangImporter/objc_bridging_generics.swift

@@ -384,3 +384,11 @@ func getContainerForPanda() -> AnimalContainer<Animal> {
 func getContainerForFungiblePanda() -> FungibleAnimalContainer<Animal & Fungible> {
   return Panda.getFungibleContainer()
 }
+
+// rdar://problem/30832766 - Infinite recursion while checking conformance
+// to AnyObject
+let third: Third! = Third()
+
+func useThird() {
+  _ = third.description
+}

test/Inputs/clang-importer-sdk/usr/include/objc_generics.h

@@ -101,3 +101,14 @@ typedef id <Fungible> FungibleObject;
 + (FungibleAnimalContainer *)getFungibleContainer;
 
 @end
+
+@interface First<__covariant T> : NSObject
+@end
+
+@interface Second<__covariant T> : First<T>
+@end
+
+@class Third;
+
+@interface Third : Second<Third *>
+@end