[wasm] Misc fixes for async compilation

test/mjsunit/regress/wasm/regress-709684.js

+// Copyright 2017 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
+
+load('test/mjsunit/wasm/wasm-constants.js');
+load('test/mjsunit/wasm/wasm-module-builder.js');
+
+let importingModuleBinary1 = (() => {
+  var builder = new WasmModuleBuilder();
+  builder.addImport('', 'f', kSig_i_v);
+  return new Int8Array(builder.toBuffer());
+})();
+
+let importingModuleBinary2 = (() => {
+  var builder = new WasmModuleBuilder();
+  builder.addImport('', 'f', kSig_i_v);
+  builder.addFunction('g', kSig_v_v)
+    .addBody([kExprNop]);
+  return new Int8Array(builder.toBuffer());
+})();
+
+let importingModuleBinary3 = (() => {
+  var builder = new WasmModuleBuilder();
+  builder.addImport('', 'f', kSig_i_v);
+  builder.addImport('', 'f2', kSig_i_v);
+  builder.addFunction('g', kSig_v_v)
+    .addBody([kExprNop]);
+  return new Int8Array(builder.toBuffer());
+})();
+
+let importingModuleBinary4 = (() => {
+  var builder = new WasmModuleBuilder();
+  builder.addFunction('g', kSig_v_v)
+    .addBody([kExprNop]);
+  return new Int8Array(builder.toBuffer());
+})();
+
+const complexImportingModuleBinary1 = (() => {
+  let builder = new WasmModuleBuilder();
+
+  builder.addImport('a', 'b', kSig_v_v);
+  builder.addImportedMemory('c', 'd', 1);
+  builder.addImportedTable('e', 'f', 1);
+  builder.addImportedGlobal('g', '⚡', kWasmI32);
+  builder.addFunction('g', kSig_v_v)
+    .addBody([kExprNop]);
+  return builder.toBuffer();
+})();
+
+const complexImportingModuleBinary2 = (() => {
+  let builder = new WasmModuleBuilder();
+
+  builder.addImport('a', 'b', kSig_v_v);
+  builder.addImportedMemory('c', 'd', 1);
+  builder.addImportedTable('e', 'f', 1);
+  builder.addImportedGlobal('g', '⚡', kWasmI32);
+  builder.addFunction('g', kSig_v_v)
+    .addBody([kExprNop]);
+  return builder.toBuffer();
+})();
+
+var tests = [
+  importingModuleBinary1,
+  importingModuleBinary2,
+  importingModuleBinary3,
+  importingModuleBinary4,
+  complexImportingModuleBinary1,
+  complexImportingModuleBinary2
+];
+
+for (var index in tests) {
+  assertPromiseResult(
+    WebAssembly.compile(tests[index]),
+    m => assertTrue(m instanceof WebAssembly.Module),
+    assertUnreachable);
+}