samples: add Terra samples

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

samples/Terra/goto.t

@@ -0,0 +1,16 @@
+
+
+terra foo()
+	var a = 0
+	::begin::
+	if a >= 10 then
+		goto theend
+	end
+	a = a + 1
+	goto begin
+	::theend::
+	return a
+end
+
+test = require("test")
+test.eq(foo(),10)