Aggregate the mentities for all the matches

Preserve the match order.

Property definitions

nitc $ IndexMatches :: mentities
	# Aggregate the mentities for all the matches
	#
	# Preserve the match order.
	fun mentities: Array[MEntity] do
		var res = new Array[MEntity]
		for match in self do res.add match.mentity
		return res
	end
src/model/model_index.nit:512,2--519,4