samples: add Terra samples

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

samples/Terra/painfulrecstruct.t

@@ -0,0 +1,22 @@
+
+
+struct A {
+	a : A -> int;
+	b : int
+}
+
+terra foo(a : A)
+	return a.b
+end
+
+terra callit(a : A)
+	return a.a(a)
+end
+
+terra bar()
+	var a = A { foo, 3 }
+	return callit(a)
+end
+
+local test = require("test")
+test.eq(bar(),3)