samples: add Terra samples

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

samples/Terra/cstruct2.t

@@ -0,0 +1,8 @@
+
+
+C = terralib.includecstring [[
+    typedef struct { int x; int y; } Point;
+    Point mkpoint() { Point p; p.x = p.y = 3; return p; }
+]]
+
+assert(C.mkpoint().x == 3)