SwSrvc Fn 0002H: Suspend Switcher

 Expects: AX    0002H
          ES:DI address of new service function handler
 Returns: CF    Carry Flag is clear (NC) is successful and...
          AX    result code: 0000H = suspended
                             0001H = not suspended, don't start
                             0002H = not suspended, OK to start
    Info: This service is used ONLY by a task-switching program that wants
          to suspend the active task switcher and provide task-switching

          Applications should not use this service.  If you need to keep a
          switcher from suspending a session, you must hook into the
          notification chain (via SwNtfyFn 0004H) and handle SwNtfyFn 0001H
          (query suspend) calls.

See Also: Switcher Services and Notifications
          INT 2fH 4bxxH (switcher functions)