samples: add Terra samples

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

samples/Terra/quote.t

@@ -0,0 +1,10 @@
+
+local c = `10
+local a = `4 + c
+terra doit()
+    var c = 3
+    return a + a
+end
+
+local test = require("test")
+test.eq(doit(),28)