samples: add Terra samples

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

samples/Terra/hello2.t

@@ -0,0 +1,10 @@
+
+local c = terralib.includec("stdio.h")
+
+terralib.tree.printraw(getmetatable(c).errors)
+
+terra main()
+	c.printf("hello, world\n")
+end
+
+main()