Remove default import

[EvanBacon]

Is your feature request related to a problem? Please describe.

AFAICT you cannot shake the default export, even if it is not included in your project.
Repro: Basic Treeshaking
Just removing react-art saves 143kb (non-gzip).

Also noting that in an RNWeb project, omitting the library react-art does not build: Issue

Describe a solution you'd like

@ide has opened a PR to remove the default import from React Native proper facebook/metro#362

We could then delete:

react-native-web/packages/react-native-web/src/index.js

Lines 218 to 325 in 8ce5750

	const ReactNative = {
	// top-level API
	createElement,
	findNodeHandle,
	render,
	unmountComponentAtNode,
	// modules
	processColor,
	NativeModules,
	TextPropTypes,
	ViewPropTypes,
	// APIs
	AccessibilityInfo,
	Alert,
	Animated,
	AppRegistry,
	AppState,
	AsyncStorage,
	BackHandler,
	Clipboard,
	DeviceInfo,
	Dimensions,
	Easing,
	I18nManager,
	InteractionManager,
	Keyboard,
	LayoutAnimation,
	Linking,
	NativeEventEmitter,
	NetInfo,
	PanResponder,
	PixelRatio,
	Platform,
	Share,
	StyleSheet,
	UIManager,
	Vibration,
	// components
	ActivityIndicator,
	ART,
	Button,
	CheckBox,
	FlatList,
	Image,
	ImageBackground,
	KeyboardAvoidingView,
	ListView,
	Modal,
	Picker,
	ProgressBar,
	RefreshControl,
	SafeAreaView,
	ScrollView,
	SectionList,
	Slider,
	StatusBar,
	SwipeableFlatList,
	SwipeableListView,
	Switch,
	Text,
	TextInput,
	Touchable,
	TouchableHighlight,
	TouchableNativeFeedback,
	TouchableOpacity,
	TouchableWithoutFeedback,
	View,
	VirtualizedList,
	YellowBox,
	// propTypes
	ColorPropType,
	EdgeInsetsPropType,
	PointPropType,
	// compat (components)
	DatePickerIOS,
	DrawerLayoutAndroid,
	ImageEditor,
	ImageStore,
	InputAccessoryView,
	MaskedViewIOS,
	NavigatorIOS,
	PickerIOS,
	ProgressBarAndroid,
	ProgressViewIOS,
	SegmentedControlIOS,
	SnapshotViewIOS,
	TabBarIOS,
	ToastAndroid,
	ToolbarAndroid,
	ViewPagerAndroid,
	WebView,
	// compat (apis)
	ActionSheetIOS,
	AlertIOS,
	CameraRoll,
	DatePickerAndroid,
	ImagePickerIOS,
	PermissionsAndroid,
	PushNotificationIOS,
	Settings,
	StatusBarIOS,
	Systrace,
	TimePickerAndroid,
	TVEventHandler,
	VibrationIOS
	};
	export default ReactNative;

Describe alternatives you've considered

• Use a plugin like deep-scope-analysis which will remove the default if there are absolutely no module.exports/requires. Unfortunately this means that react-art would still get bundled (amongst others).

Additional context

N/A