samples: add Terra samples

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

samples/Terra/point.t

@@ -0,0 +1,13 @@
+
+terra bar(a : &int)
+    @a = @a + 1
+end
+terra foo(a : int) : int
+    var b : int
+    b = a
+    bar(&b)
+    return b
+end
+
+local test = require("test")
+test.eq(foo(4),5)