remove arguments-to-array helper

lib/6to5/file.js

@@ -22,7 +22,6 @@ File.declarations = [
   "tagged-template-literal",
   "interop-require",
   "to-array",
-  "arguments-to-array",
   "object-spread",
   "has-own",
   "slice"
@@ -81,14 +80,11 @@ File.normaliseOptions = function (opts) {
 File.prototype.toArray = function (node) {
   if (t.isArrayExpression(node)) {
     return node;
+  } else if (t.isIdentifier(node) && node.name === "arguments") {
+    return t.callExpression(t.memberExpression(this.addDeclaration("slice"), t.identifier("call")), [node]);
+  } else {
+    return t.callExpression(this.addDeclaration("to-array"), [node]);
   }
-
-  var templateName = "to-array";
-  if (t.isIdentifier(node) && node.name === "arguments") {
-    templateName = "arguments-to-array";
-  }
-
-  return t.callExpression(this.addDeclaration(templateName), [node]);
 };
 
 File.prototype.getModuleFormatter = function (type) {

lib/6to5/templates/arguments-to-array.js

@@ -1,7 +0,0 @@
-(function (args) {
-  var target = new Array(args.length);
-  for (var i = 0; i< args.length; i++) {
-    target[i] = args[i];
-  }
-  return target;
-})

lib/6to5/transformation/transformers/es6-rest-parameters.js

@@ -8,13 +8,10 @@ exports.Function = function (node, parent, file) {
 
   t.ensureBlock(node);
 
-  var call = t.callExpression(
-    file.addDeclaration("arguments-to-array"),
-    [t.identifier("arguments")]
-  );
+  var call = file.toArray(t.identifier("arguments"));
 
   if (node.params.length) {
-    call = t.callExpression(t.memberExpression(call, t.identifier("slice")), [t.literal(node.params.length)]);
+    call.arguments.push(t.literal(node.params.length));
   }
 
   call._ignoreAliasFunctions = true;