Does the MPropDef contains a call to super or a call of a super-constructor?

Subsequent phases of the frontend (esp. typing) set it if required

Property definitions

nitc :: modelize_property $ MPropDef :: has_supercall
	# Does the MPropDef contains a call to super or a call of a super-constructor?
	# Subsequent phases of the frontend (esp. typing) set it if required
	var has_supercall: Bool = false is writable
src/modelize/modelize_property.nit:512,2--514,44