Generate a return with value

Property definitions

nitc $ JavaCompilerVisitor :: ret
	# Generate a return with `value`
	fun ret(value: RuntimeVariable) do
		var frame = self.frame
		assert frame != null
		var returnvar = frame.returnvar
		if returnvar != null then
			assign(returnvar, value)
		end
		self.add("break {frame.returnlabel.as(not null)};")
	end
src/compiler/java_compiler.nit:762,2--771,4