samples: add Terra samples

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

samples/Terra/hello.t

@@ -0,0 +1,8 @@
+local c = terralib.includec("stdio.h")
+
+terra hello()
+	c.printf("hello, world\n")
+end
+
+terralib.saveobj("hello",{main = hello})
+hello()