RemoteInspection: Add IsComplete flag to AsyncTaskInfo (#80183)

This will be used by lldb. I'd like to add it to swift-inspect too, but that will require figuring out how to evolve the swift runtime's ABI.

rdar://147448235

Author: kastiglione

include/swift/RemoteInspection/ReflectionContext.h

@@ -194,6 +194,7 @@ class ReflectionContext
     bool HasIsRunning; // If false, the IsRunning flag is not valid.
     bool IsRunning;
     bool IsEnqueued;
+    bool IsComplete;
 
     bool HasThreadPort;
     uint32_t ThreadPort;
@@ -1779,6 +1780,7 @@ class ReflectionContext
         TaskStatusFlags & ActiveTaskStatusFlags::IsStatusRecordLocked;
     Info.IsEscalated = TaskStatusFlags & ActiveTaskStatusFlags::IsEscalated;
     Info.IsEnqueued = TaskStatusFlags & ActiveTaskStatusFlags::IsEnqueued;
+    Info.IsComplete = TaskStatusFlags & ActiveTaskStatusFlags::IsComplete;
 
     setIsRunning(Info, AsyncTaskObj.get());
     std::tie(Info.HasThreadPort, Info.ThreadPort) =