static EncodedJSValue JSC_HOST_CALL constructJSWebAssemblyModule(ExecState* state)
{
    VM& vm = state->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);
    JSValue val = state->argument(0);

    // If the given bytes argument is not a BufferSource, a TypeError exception is thrown.
    JSArrayBuffer* arrayBuffer = val.getObject() ? jsDynamicCast<JSArrayBuffer*>(val.getObject()) : nullptr;
    JSArrayBufferView* arrayBufferView = val.getObject() ? jsDynamicCast<JSArrayBufferView*>(val.getObject()) : nullptr;
    if (!(arrayBuffer || arrayBufferView))
        return JSValue::encode(throwException(state, scope, createTypeError(state, ASCIILiteral("first argument to WebAssembly.Module must be an ArrayBufferView or an ArrayBuffer"), defaultSourceAppender, runtimeTypeForValue(val))));

    if (arrayBufferView ? arrayBufferView->isNeutered() : arrayBuffer->impl()->isNeutered())
        return JSValue::encode(throwException(state, scope, createTypeError(state, ASCIILiteral("underlying TypedArray has been detatched from the ArrayBuffer"), defaultSourceAppender, runtimeTypeForValue(val))));

    size_t byteOffset = arrayBufferView ? arrayBufferView->byteOffset() : 0;
    size_t byteSize = arrayBufferView ? arrayBufferView->length() : arrayBuffer->impl()->byteLength();
    const auto* base = arrayBufferView ? static_cast<uint8_t*>(arrayBufferView->vector()) : static_cast<uint8_t*>(arrayBuffer->impl()->data());

    Wasm::Plan plan(&vm, base + byteOffset, byteSize);
    // On failure, a new WebAssembly.CompileError is thrown.
    plan.run();
    if (plan.failed())
        return JSValue::encode(throwException(state, scope, createWebAssemblyCompileError(state, plan.errorMessage())));

    // On success, a new WebAssembly.Module object is returned with [[Module]] set to the validated Ast.module.
    auto* structure = InternalFunction::createSubclassStructure(state, state->newTarget(), asInternalFunction(state->jsCallee())->globalObject()->WebAssemblyModuleStructure());
    RETURN_IF_EXCEPTION(scope, { });

    // The export symbol table is the same for all Instances of a Module.
    SymbolTable* exportSymbolTable = SymbolTable::create(vm);
    for (auto& exp : plan.exports()) {
        auto offset = exportSymbolTable->takeNextScopeOffset(NoLockingNecessary);
        exportSymbolTable->set(NoLockingNecessary, exp.field.impl(), SymbolTableEntry(VarOffset(offset)));
    }

    // Only wasm-internal functions have a callee, stubs to JS do not.
    unsigned calleeCount = plan.internalFunctionCount();
    JSWebAssemblyModule* result = JSWebAssemblyModule::create(vm, structure, plan.takeModuleInformation(), plan.takeCallLinkInfos(), plan.takeWasmToJSStubs(), plan.takeFunctionIndexSpace(), exportSymbolTable, calleeCount);
    plan.initializeCallees(state->jsCallee()->globalObject(), 
        [&] (unsigned calleeIndex, JSWebAssemblyCallee* jsEntrypointCallee, JSWebAssemblyCallee* wasmEntrypointCallee) {
            result->setJSEntrypointCallee(vm, calleeIndex, jsEntrypointCallee);
            result->setWasmEntrypointCallee(vm, calleeIndex, wasmEntrypointCallee);
        });
    return JSValue::encode(result);
}
JSValue WebAssemblyModuleConstructor::createModule(ExecState* state, Structure* structure)
{
    VM& vm = state->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    size_t byteOffset;
    size_t byteSize;
    uint8_t* base = getWasmBufferFromValue(state, state->argument(0), byteOffset, byteSize);
    RETURN_IF_EXCEPTION(scope, { });

    Wasm::Plan plan(&vm, base + byteOffset, byteSize);
    // On failure, a new WebAssembly.CompileError is thrown.
    plan.run();
    if (plan.failed())
        return throwException(state, scope, createJSWebAssemblyCompileError(state, vm, plan.errorMessage()));

    // On success, a new WebAssembly.Module object is returned with [[Module]] set to the validated Ast.module.

    // The export symbol table is the same for all Instances of a Module.
    SymbolTable* exportSymbolTable = SymbolTable::create(vm);
    for (auto& exp : plan.exports()) {
        auto offset = exportSymbolTable->takeNextScopeOffset(NoLockingNecessary);
        exportSymbolTable->set(NoLockingNecessary, exp.field.impl(), SymbolTableEntry(VarOffset(offset)));
    }

    // Only wasm-internal functions have a callee, stubs to JS do not.
    unsigned calleeCount = plan.internalFunctionCount();
    JSWebAssemblyModule* result = JSWebAssemblyModule::create(vm, structure, plan.takeModuleInformation(), plan.takeCallLinkInfos(), plan.takeWasmExitStubs(), exportSymbolTable, calleeCount);
    plan.initializeCallees(state->jsCallee()->globalObject(), 
        [&] (unsigned calleeIndex, JSWebAssemblyCallee* jsEntrypointCallee, JSWebAssemblyCallee* wasmEntrypointCallee) {
            result->setJSEntrypointCallee(vm, calleeIndex, jsEntrypointCallee);
            result->setWasmEntrypointCallee(vm, calleeIndex, wasmEntrypointCallee);
        });

    return result;
}