Add test that exercises still overriding ObjC async methods as completion handlers

Author: jckarter

test/Concurrency/Runtime/Inputs/objc_async.h

@@ -8,6 +8,12 @@
 
 @end
 
+@interface MutableButt: Butt
+@end
+
+@interface MutableButt_2Fast2Furious: MutableButt
+@end
+
 @interface Farm: NSObject
 
 -(void)getDogWithCompletion:(void (^ _Nonnull)(NSInteger))completionHandler

test/Concurrency/Runtime/Inputs/objc_async.m

@@ -14,6 +14,13 @@ - (void)butt:(NSInteger)x completionHandler:(void (^)(NSInteger))handler {
 
 @end
 
+@implementation MutableButt: Butt
+@end
+
+@implementation MutableButt_2Fast2Furious: MutableButt
+@end
+
+
 @implementation Farm
 
 -(void)getDogWithCompletion:(void (^ _Nonnull)(NSInteger))completionHandler {
@@ -30,7 +37,7 @@ -(void)obtainCat:(void (^ _Nonnull)(NSInteger, NSError* _Nullable))completionHan
 
 void scheduleButt(Butt *b, NSString *s) {
   [b butt: 1738 completionHandler: ^(NSInteger i) {
-    printf("butt %p named %s occurred at %zd", b, [s UTF8String], (ssize_t)i);
+    printf("butt %p named %s occurred at %zd\n", b, [s UTF8String], (ssize_t)i);
     fflush(stdout);
   }];
 }

test/Concurrency/Runtime/objc_async.swift

@@ -31,7 +31,14 @@ func farmTest() async {
 class Clbuttic: Butt {
     override func butt(_ x: Int) async -> Int {
         print("called into override")
-        return 679
+        return 219
+    }
+}
+
+class Buttertion: MutableButt_2Fast2Furious {
+    override func butt(_ x: Int, completionHandler: @escaping (Int) -> Void) {
+        print("called again into override")
+        completionHandler(20721)
     }
 }
 
@@ -48,10 +55,16 @@ class Clbuttic: Butt {
     await farmTest()
 
     // CHECK-NEXT: called into override
-    // CHECK-NEXT: butt {{.*}} named clbuttic occurred at 679
+    // CHECK-NEXT: butt {{.*}} named clbuttic occurred at 219
     scheduleButt(Clbuttic(), "clbuttic")
 
-    await Task.sleep(500_000)
+    await Task.sleep(250_000)
+
+    // CHECK-NEXT: called again into override
+    // CHECK-NEXT: butt {{.*}} named buttertion occurred at 20721
+    scheduleButt(Buttertion(), "buttertion")
+
+    await Task.sleep(250_000)
   }
 }