samples: add Terra samples

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

samples/Terra/terraluamethod.t

@@ -0,0 +1,16 @@
+struct A { a : int }
+
+A.methods.up = function(self,b)
+	self.a = self.a + 1 + (b or 0)
+end
+
+terra foo()
+	var a = A { 1 }
+	a:up()
+	var b = &a
+	b:up(4)
+	return a.a
+end
+
+local test = require("test")
+test.eq(foo(),7)