[wasm] Fix validation error for missing return statement in asm.js module.

test/mjsunit/regress/regress-575364.js

Index: test/mjsunit/regress/regress-575364.js
diff --git a/test/mjsunit/regress/regress-crbug-504787.js b/test/mjsunit/regress/regress-575364.js
similarity index 69%
copy from test/mjsunit/regress/regress-crbug-504787.js
copy to test/mjsunit/regress/regress-575364.js
index 66274bc6b9e314917b098349437c20cc1318888c..369a906a3d17e4f347e8307f48e0d790041eea6f 100644
--- a/test/mjsunit/regress/regress-crbug-504787.js
+++ b/test/mjsunit/regress/regress-575364.js
@@ -2,14 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --noturbo-osr
+// Flags:  --expose-wasm
 
 function f() {
   "use asm";
-  function g() {
-    function f() {};
-  }
-  return g;
-}
 
-f()();
+}
+assertThrows(function() { WASM.asmCompileRun(f.toString()); });