[TaskGroup] simplify throw_recover test a little bit

Author: ktoso

test/Concurrency/Runtime/async_taskgroup_throw_recover.swift

@@ -14,64 +14,45 @@ func boom() async throws -> Int {
 }
 
 func test_taskGroup_throws() async {
-  do {
-    print("start \(#function)")
-    let got = try! await Task.withGroup(resultType: Int.self) {
-      group async throws -> Int in
-      await group.add { await one() }
-      await group.add { try await boom()  }
+  let got: Int = try! await Task.withGroup(resultType: Int.self) { group in
+    await group.add { try await boom()  }
 
-      do {
-        while let r = try await group.next() {
-          print("next: \(r)")
-        }
-      } catch {
-        print("error caught in group: \(error)")
-
-        await group.add { () async -> Int in
-          let c = await Task.__unsafeCurrentAsync().isCancelled
-          print("task 3 (cancelled: \(c))")
-          return 3
-        }
-
-        guard let got = try! await group.next() else {
-          print("task group failed to get 3 (:\(#line))")
-          return 0
-        }
+    do {
+      while let r = try await group.next() {
+        print("next: \(r)")
+      }
+    } catch {
+      print("error caught in group: \(error)")
 
-        print("task group next: \(got)")
+      let gc = group.isCancelled
+      print("group cancelled: \(gc)")
 
-        if got == 1 {
-          // the previous 1 completed before the 3 we just submitted,
-          // we still want to see that three so let's await for it
-          guard let third = try! await group.next() else {
-            print("task group failed to get 3 (:\(#line))")
-            return got
-          }
+      await group.add { () async -> Int in
+        let c = await Task.__unsafeCurrentAsync().isCancelled
+        print("task 3 (cancelled: \(c))")
+        return 3
+      }
 
-          print("task group returning normally: \(third)")
-          return third
-        } else {
-          print("task group returning normally: \(got)")
-          return got
-        }
+      guard let third = try! await group.next() else {
+        print("task group failed to get 3")
+        return 0 
       }
 
-      fatalError("Should have thrown and handled inside the catch block")
+      print("task group returning normally: \(third)")
+      return third
     }
 
-    // Optionally, we may get the first result back before the failure:
-    // COM: next: 1
-    // CHECK: error caught in group: Boom()
-    // CHECK: task 3 (cancelled: false)
-    // CHECK: task group returning normally: 3
-    // CHECK: got: 3
-
-    print("got: \(got)")
-  } catch {
-    print("rethrown: \(error)")
-    fatalError("Expected recovered result, but got error: \(error)")
+    fatalError("Should have thrown and handled inside the catch block")
   }
+
+  // Optionally, we may get the first result back before the failure:
+  // CHECK: error caught in group: Boom()
+  // CHECK: group cancelled: false
+  // CHECK: task 3 (cancelled: false)
+  // CHECK: task group returning normally: 3
+  // CHECK: got: 3
+
+  print("got: \(got)")
 }