samples: add Terra samples

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

samples/Terra/def1.t

@@ -0,0 +1,16 @@
+import "lib/def"
+
+local c = 3
+local a = 4
+local b = def(a) a + c
+local d = b(10)
+
+def e(a) a + c
+local def f(a) a + c
+
+print(d, e(10), f(10)) 
+
+local test = require("test")
+test.eq(d,13)
+test.eq(e(10),13)
+test.eq(f(10),13)