gflib.ts: put warning on console when function undefined

src/runtime/typescript/gflib.ts

@@ -377,6 +377,7 @@ class GFConcrete {
       for (let i in cs) {
         if (isUndefined(cs[i])) {
           // Some arguments into this function are undefined
+          console.warn(`${tree.args[i].name} is undefined`)
           return [{
             fid: -5, // signal to parent that I cannot lin properly
             table: [[new SymKS(`[${tree.name}]`).tagWith(tag)]]

src/runtime/typescript/js/gflib.js

@@ -304,6 +304,7 @@ var GFConcrete = (function () {
             var key = tree.name;
             for (var i in cs_1) {
                 if (isUndefined(cs_1[i])) {
+                    console.warn(tree.args[i].name + " is undefined");
                     return [{
                             fid: -5,
                             table: [[new SymKS("[" + tree.name + "]").tagWith(tag)]]