samples: add Terra samples

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

samples/Terra/anonstruct.t

@@ -0,0 +1,12 @@
+
+local C = tuple(int,tuple(int,int))
+terra anon()
+    var c : tuple(int,tuple(int,int)) = { 1, {2,3} }
+    var d : C = c
+    d._0 = 2
+    return d._0 + c._1._0 + c._1._1
+end
+
+test = require("test")
+
+test.eq(anon(),7)