Implement LinkError; import tweaks

test/mjsunit/wasm/export-table.js

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --expose-wasm
 
 load("test/mjsunit/wasm/wasm-constants.js");
 load("test/mjsunit/wasm/wasm-module-builder.js");
 
 (function testExportedMain() {
@@ skipping 36 matching lines @@
 
   assertEquals("object", typeof module.exports);
   assertEquals("function", typeof module.exports.blah);
   assertEquals("function", typeof module.exports.foo);
 
   assertEquals(kReturnValue, module.exports.foo());
   assertEquals(kReturnValue, module.exports.blah());
   assertSame(module.exports.blah, module.exports.foo);
 })();
 
+(function testEmptyName() {
+  print("TestEmptyName...");
+  var kReturnValue = 93;
+
+  var builder = new WasmModuleBuilder();
+
+  builder.addFunction("main", kSig_i_v)
+    .addBody([
+      kExprI8Const,
+      kReturnValue,
+      kExprReturn
+    ])
+    .exportAs("");
+
+  var module = builder.instantiate();
+
+  assertEquals("object", typeof module.exports);
+  assertEquals("function", typeof module.exports[""]);
+
+  assertEquals(kReturnValue, module.exports[""]());
+})();
 
 (function testNumericName() {
   print("TestNumericName...");
   var kReturnValue = 93;
 
   var builder = new WasmModuleBuilder();
 
   builder.addFunction("main", kSig_i_v)
     .addBody([
       kExprI8Const,
@@ skipping 38 matching lines @@
 
   let instance = builder.instantiate();
   let e = instance.exports;
   assertEquals("function", typeof e.a);
   assertEquals("function", typeof e.b);
   assertEquals("function", typeof e.c);
   assertSame(e.a, e.b);
   assertSame(e.a, e.c);
   assertEquals(String(f.index), e.a.name);
 })();