Determines which registers are returned or set when using NativeMethods.GetThreadContext or NativeMethods.SetThreadContext. If the context record is used as an INPUT parameter, then for each portion of the context record controlled by a flag whose value is set, it is assumed that portion of the context record contains valid context. If the context record is being used to modify a threads context, then only that portion of the threads context will be modified. If the context record is used as an INPUT/OUTPUT parameter to capture the context of a thread, then only those portions of the thread's context corresponding to set flags will be returned. The context record is never used as an OUTPUT only parameter.
