[wasm][asm.js] Require exported asm.js functions have be names.

test/mjsunit/wasm/asm-wasm.js

Index: test/mjsunit/wasm/asm-wasm.js
diff --git a/test/mjsunit/wasm/asm-wasm.js b/test/mjsunit/wasm/asm-wasm.js
index e7124f86744f6a71dc837bb82be91aea2320aa45..3d302c5f7a043acc9eaccfa267e71f0eed08d945 100644
--- a/test/mjsunit/wasm/asm-wasm.js
+++ b/test/mjsunit/wasm/asm-wasm.js
@@ -1484,6 +1484,19 @@ assertWasm(-34359738370.75, TestNegativeDouble);
 })();
 
 
+(function TestBadExportKey() {
+  function Module() {
+    "use asm";
+    function func() {
+    }
+    return {123: func};
+  }
+
+  Module(stdlib);
+  assertTrue(%IsNotAsmWasmCode(Module));
+})();
+
+
 function TestAndIntAndHeapValue(stdlib, foreign, buffer) {
   "use asm";
   var HEAP32 = new stdlib.Int32Array(buffer);