Added 'loops' test case.

This script tests the generic for loop using a Lua closure as the iterator
function, which is currently broken.

src/test/res/loops.lua

@@ -0,0 +1,22 @@
+-- This script tests the "generic" for loop with a script iterator.
+
+local function stuff()
+	local function i(o)
+		if o.counter > 3 then
+			return nil
+		else
+			local v = o.counter
+			o.counter = v + 1
+			return v
+		end
+	end
+	return i, { counter=1 }
+end
+
+local function testfor()
+	for x in stuff() do
+		print(x)
+	end
+end
+
+testfor()