[wasm] Implement WebAssembly.Module.exports function.

test/mjsunit/wasm/js-api.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 --allow-natives-syntax
 
 if ((typeof drainJobQueue) != "function") {
   drainJobQueue = () => { %RunMicrotasks() };
 }
 
@@ skipping 176 matching lines @@
 assertEq(arr[1].kind, "memory");
 assertEq(arr[1].module, "c");
 assertEq(arr[1].name, "d");
 assertEq(arr[2].kind, "table");
 assertEq(arr[2].module, "e");
 assertEq(arr[2].name, "f");
 assertEq(arr[3].kind, "global");
 assertEq(arr[3].module, "g");
 assertEq(arr[3].name, "x");
 
-if (false) { // TODO: Module.exports property
 // 'WebAssembly.Module.exports' data property
 let moduleExportsDesc = Object.getOwnPropertyDescriptor(Module, 'exports');
 assertEq(typeof moduleExportsDesc.value, "function");
 assertEq(moduleExportsDesc.writable, true);
 assertEq(moduleExportsDesc.enumerable, false);
 assertEq(moduleExportsDesc.configurable, true);
 
 // 'WebAssembly.Module.exports' method
 let moduleExports = moduleExportsDesc.value;
 assertEq(moduleExports.length, 1);
 assertErrorMessage(() => moduleExports(), TypeError, /requires more than 0 arguments/);
 assertErrorMessage(() => moduleExports(undefined), TypeError, /first argument must be a WebAssembly.Module/);
 assertErrorMessage(() => moduleExports({}), TypeError, /first argument must be a WebAssembly.Module/);
 var arr = moduleExports(emptyModule);
 assertEq(arr instanceof Array, true);
 assertEq(arr.length, 0);
-var arr = moduleExports(new Module(wasmTextToBinary('(module (func (export "a")) (memory (export "b") 1) (table (export "c") 1 anyfunc) (global (export "⚡") i32 (i32.const 0)))')));
+let exportingModuleBinary2 = (() => {
+  var text =
+  '(module (func (export "a")) (memory (export "b") 1) (table (export "c") 1 anyfunc) (global (export "⚡") i32 (i32.const 0)))';
+  let builder = new WasmModuleBuilder();
+  builder.addFunction("foo", kSig_v_v)
+    .addBody([])
+    .exportAs("a");
+  builder.addMemory(1, 1, false);
+  builder.exportMemoryAs("b");
+  builder.setFunctionTableLength(1);
+  builder.addExportOfKind("c", kExternalTable, 0);
+  var o = builder.addGlobal(kWasmI32, false)
+      .exportAs("x");
+  return new Int8Array(builder.toBuffer());
+})();
+var arr = moduleExports(new Module(exportingModuleBinary2));
 assertEq(arr instanceof Array, true);
 assertEq(arr.length, 4);
 assertEq(arr[0].kind, "function");
 assertEq(arr[0].name, "a");
 assertEq(arr[1].kind, "memory");
 assertEq(arr[1].name, "b");
 assertEq(arr[2].kind, "table");
 assertEq(arr[2].name, "c");
 assertEq(arr[3].kind, "global");
-assertEq(arr[3].name, "⚡");
-}
+assertEq(arr[3].name, "x");
 
 // 'WebAssembly.Instance' data property
 let instanceDesc = Object.getOwnPropertyDescriptor(WebAssembly, 'Instance');
 assertEq(typeof instanceDesc.value, "function");
 assertEq(instanceDesc.writable, true);
 assertEq(instanceDesc.enumerable, false);
 assertEq(instanceDesc.configurable, true);
 
 // 'WebAssembly.Instance' constructor function
 let Instance = WebAssembly.Instance;
@@ skipping 348 matching lines @@
       assertEq(result.instance instanceof Instance, true);
     }
   }
   assertInstantiateSuccess(emptyModule);
   assertInstantiateSuccess(emptyModuleBinary);
   assertInstantiateSuccess(emptyModuleBinary.buffer);
   assertInstantiateSuccess(importingModule, {"":{f:()=>{}}});
   assertInstantiateSuccess(importingModuleBinary, {"":{f:()=>{}}});
   assertInstantiateSuccess(importingModuleBinary.buffer, {"":{f:()=>{}}});
 }