samples: add Terra samples

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

samples/Terra/incomplete2.t

@@ -0,0 +1,25 @@
+
+struct A {
+	b : &B
+} and
+struct B
+
+
+terra foo()
+	var a : A
+	a.b = nil
+	return a
+end
+
+local a = foo()
+
+
+struct B {
+	a : int
+}
+
+terra foo2(a : &A)
+	a.b = a.b + 1
+end
+
+foo2(a)