[wasm] Add test for reexport of the same import twice.

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 115 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);
 })();
+
+
+(function testReexportJSMultipleIdentity() {
+  print("TestReexportMultipleIdentity...");
+  var builder = new WasmModuleBuilder();
+
+  function js() {}
+
+  var a = builder.addImport("a", kSig_v_v);
+  var b = builder.addImport("a", kSig_v_v);
+  builder.addExport("f", a);
+  builder.addExport("g", b);
+
+  let instance = builder.instantiate({a: js, b: js});

[Clemens Hammacher, 2016/12/20 09:51:39]

b is not needed here

[titzer, 2016/12/20 10:13:45]

Actually that was a bug in the test. Good catch. Fixed this and added a second
test for another case.

+  let e = instance.exports;
+  assertEquals("function", typeof e.f);
+  assertEquals("function", typeof e.g);
+  assertFalse(e.f == js);
+  assertFalse(e.g == js);
+  assertFalse(e.f == e.g);
+})();