Check in codegen test expectations.

test/codegen/expect/varargs.js

+dart_library.library('varargs', null, /* Imports */[
+  'dart_sdk'
+], function load__varargs(exports, dart_sdk) {
+  'use strict';
+  const core = dart_sdk.core;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const varargs = Object.create(null);
+  let dynamicAnddynamicTodynamic = () => (dynamicAnddynamicTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [dart.dynamic, dart.dynamic])))();
+  varargs.varargsTest = function(x, ...others) {
+    let args = [1, others];
+    dart.dsend(x, 'call', ...args);
+  };
+  dart.fn(varargs.varargsTest, dynamicAnddynamicTodynamic());
+  varargs.varargsTest2 = function(x, ...others) {
+    let args = [1, others];
+    dart.dsend(x, 'call', ...args);
+  };
+  dart.fn(varargs.varargsTest2, dynamicAnddynamicTodynamic());
+  // Exports:
+  exports.varargs = varargs;
+});