The `isa` keyword

Property definitions

	# The `isa` keyword
	var n_kwisa: TKwisa is writable, noinit

src/parser/parser_nodes.nit:2277,2--2278,40

	redef fun n_kwisa=(node)
	do
		_n_kwisa = node
		node.parent = self
	end

src/parser/parser_prod.nit:4440,2--4444,4