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

R=clemensh@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2592563003
Cr-Commit-Position: refs/heads/master@{#41850}

test/mjsunit/wasm/export-table.js

@@ -133,3 +133,44 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   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);
+  builder.addExport("f", a);
+  builder.addExport("g", a);
+
+  let instance = builder.instantiate({a: js});
+  let e = instance.exports;
+  assertEquals("function", typeof e.f);
+  assertEquals("function", typeof e.g);
+  assertFalse(e.f == js);
+  assertFalse(e.g == js);
+  assertTrue(e.f == e.g);
+})();
+
+
+(function testReexportJSMultiple() {
+  print("TestReexportMultiple...");
+  var builder = new WasmModuleBuilder();
+
+  function js() {}
+
+  var a = builder.addImport("a", kSig_v_v);
+  var b = builder.addImport("b", kSig_v_v);
+  builder.addExport("f", a);
+  builder.addExport("g", b);
+
+  let instance = builder.instantiate({a: js, b: js});
+  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);
+})();