samples: add Terra samples

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

samples/Terra/structrvalue.t

@@ -0,0 +1,16 @@
+--the zero line
+struct A { b : B } and
+struct B {a : int, b : int}
+
+
+terra foo()
+	var b = B {1,2}
+	return b
+end
+
+terra bar()
+	return foo().b
+end
+
+local test = require("test")
+test.eq(bar(),2)