Flags used internally to know which pipe to open

Property definitions

	# Flags used internally to know which pipe to open
	private fun pipeflags: Int do return 0

lib/core/exec.nit:98,2--99,39

	redef fun pipeflags do return 2

lib/core/exec.nit:356,2--32

	redef fun pipeflags do return 1

lib/core/exec.nit:379,2--32

	redef fun pipeflags do return 3

lib/core/exec.nit:402,2--32