samples: add Terra samples

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

samples/Terra/luabridgerec.t

@@ -0,0 +1,10 @@
+
+struct A { a : &A, b : int }
+
+terra foo(a : A)
+    return a.b
+end
+
+local test = require("test")
+
+test.eq(foo({b = 5}),5)