samples: add Terra samples

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

samples/Terra/overload2.t

@@ -0,0 +1,15 @@
+
+terra foo(a : int)
+	return 1
+end
+
+terra foo(a : double)
+	return 2
+end
+
+terra doit()
+	return foo(2.5)
+end
+
+local test = require("test")
+test.eq(doit(),2)