Check in codegen test expectations.

test/codegen/expect/language/regress_23046_test.js

Index: test/codegen/expect/language/regress_23046_test.js
diff --git a/test/codegen/expect/language/regress_23046_test.js b/test/codegen/expect/language/regress_23046_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..3404b9e5c12b0b9dfe9e8408852490d0757b4aa1
--- /dev/null
+++ b/test/codegen/expect/language/regress_23046_test.js
@@ -0,0 +1,22 @@
+dart_library.library('language/regress_23046_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__regress_23046_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 regress_23046_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  regress_23046_test.y = 'foo';
+  regress_23046_test.x = dart.str`${regress_23046_test.y}"`;
+  regress_23046_test.m = dart.const(dart.map([regress_23046_test.x, 0, regress_23046_test.y, 1]));
+  regress_23046_test.main = function() {
+    expect$.Expect.equals(regress_23046_test.x, 'foo"');
+    expect$.Expect.equals(regress_23046_test.m[dartx.length], 2);
+  };
+  dart.fn(regress_23046_test.main, VoidTodynamic());
+  // Exports:
+  exports.regress_23046_test = regress_23046_test;
+});