Safely show a debug message on the current node and repeat the message in the C code as a comment

Property definitions

nitc $ AbstractCompilerVisitor :: debug
	# Safely show a debug message on the current node and repeat the message in the C code as a comment
	fun debug(message: String)
	do
		var node = self.current_node
		if node == null then
			print "?: {message}"
		else
			node.debug(message)
		end
		self.add("/* DEBUG: {message} */")
	end
src/compiler/abstract_compiler.nit:2043,2--2053,4