Check in codegen test expectations.

test/codegen/expect/language/double_to_string_as_exponential3_test.js

Index: test/codegen/expect/language/double_to_string_as_exponential3_test.js
diff --git a/test/codegen/expect/language/double_to_string_as_exponential3_test.js b/test/codegen/expect/language/double_to_string_as_exponential3_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..9b909ff612f9a11510b5d5fa70acff7fd4cbbff3
--- /dev/null
+++ b/test/codegen/expect/language/double_to_string_as_exponential3_test.js
@@ -0,0 +1,20 @@
+dart_library.library('language/double_to_string_as_exponential3_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__double_to_string_as_exponential3_test(exports, dart_sdk, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const expect$ = expect.expect;
+  const double_to_string_as_exponential3_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  double_to_string_as_exponential3_test.main = function() {
+    expect$.Expect.equals("1.00000000000000000000e+0", 1.0[dartx.toStringAsExponential](20));
+    expect$.Expect.equals("1.00000000000000005551e-1", 0.1[dartx.toStringAsExponential](20));
+    expect$.Expect.equals(0.1, 0.1);
+  };
+  dart.fn(double_to_string_as_exponential3_test.main, VoidTodynamic());
+  // Exports:
+  exports.double_to_string_as_exponential3_test = double_to_string_as_exponential3_test;
+});