remove redundant file

treegen.js

@@ -1,20 +0,0 @@
-#!  /usr/bin/node
-
-var parser = require("./parse.js");
-var pprint = require("./pprint.js");
-var repr = require("./representation.js");
-var lex = require("./tokenize.js");
-
-var qc = require("quickcheck");
-
-function arbIdentifier() {
-    var st = qc.arbString()
-    if (lex.isIdentifier(st)) {
-      return new repr.Name(st);
-    }
-    else {
-      return arbIdentifier();
-    }
-}
-
-console.log(arbIdentifier());