new_contents: import simuvex
  
  ######################################
  # NoReturnUnconstrained
  # Use in places you would put ReturnUnconstrained as a default action
  # But the function shouldn't actually return
  ######################################
  
  use_cases = {'exit_group', 'exit', 'abort', 'longjmp', 'pthread_exit', 'siglongjmp'}
  
  class NoReturnUnconstrained(simuvex.SimProcedure): #pylint:disable=redefined-builtin
      NO_RET = True
      def run(self): #pylint:disable=unused-argument
          return
  
subject: Add NoReturnUnconstrained and its use cases