[wasm][asm.js] Ignore duplicate exports in asm.js.

test/mjsunit/asm/asm-validation.js

Index: test/mjsunit/asm/asm-validation.js
diff --git a/test/mjsunit/asm/asm-validation.js b/test/mjsunit/asm/asm-validation.js
index 0c9e841fe94ad4b95ac0579b482cf5ed9b41ccb5..db355234750ee7266e3812002b176360ceaf0aac 100644
--- a/test/mjsunit/asm/asm-validation.js
+++ b/test/mjsunit/asm/asm-validation.js
@@ -316,6 +316,18 @@ function assertValidAsm(func) {
   assertEquals(3, m.foo(3));
 })();
 
+(function TestBadExportTwice() {
+  function Module() {
+    "use asm";
+    function bar() { return 1; }
+    function baz() { return 2; }
+    return {foo: bar, foo: baz};
+  }
+  var m = Module();
+  assertTrue(%IsAsmWasmCode(Module));
+  assertEquals(2, m.foo());
+})();
+
 (function TestBadImport() {
   function Module(stdlib) {
     "use asm";