samples: add Terra samples

source: https://github.com/zdevito/terra/tree/master/tests

samples/Terra/class4.t

@@ -0,0 +1,22 @@
+J = require("lib/javalike")
+
+struct Shape {
+	foo : int
+}
+
+Drawable = J.interface { draw = {} -> {} }
+
+struct Square {
+	length : int 
+}
+J.extends(Square,Shape)
+J.implements(Square,Drawable)
+
+terra Square:draw() : {}  end
+
+terra bar()
+ var a : &Square = Square.alloc()
+ a:draw()
+end
+
+bar()