Fix test/IRGen/objc_generic_class_stub.swift again

More FileCheck shenanigans.

Fixes <rdar://problem/71560719>.

Author: slavapestov

test/IRGen/objc_generic_class_stub.swift

@@ -14,6 +14,6 @@ public class ConcreteNSObjectSubclass : GenericNSObjectSubclass<Int> {}
 // Note the stub here is internal; it's only purpose is to appear in the stub list
 // so that it can be realized by objc_copyClassList():
 
-// CHECK-LABEL: @"$s23objc_generic_class_stub24ConcreteNSObjectSubclassCMt" = internal global %objc_full_class_stub { {{i32|i64}} 0, {{i32|i64}} 1, %objc_class* (%objc_class*, i8*)* @"$s23objc_generic_class_stub24ConcreteNSObjectSubclassCMU" }
+// CHECK-LABEL: @"$s23objc_generic_class_stub24ConcreteNSObjectSubclassCMt" = internal global %objc_full_class_stub {{.*}} @"$s23objc_generic_class_stub24ConcreteNSObjectSubclassCMU{{(\.ptrauth)?}}"
 
 // CHECK-LABEL: @objc_class_stubs = internal global {{.*}} @"$s23objc_generic_class_stub24ConcreteNSObjectSubclassCMt" {{.*}}, section "__DATA,__objc_stublist,regular,no_dead_strip"