fix(ReactInstance): Set bridge instance before calling LoadScript (#745)
fix(ReactInstance): Set bridge instance before calling LoadScript (#745)

JavaScript may call native behaviors prior to the `_bridge` variable being set in `ReactInstance`, which would be invoked in the initial call to `FlushedQueue` following the call to run the bundle.

This change set ensures the `_bridge` is set before the bundle is loaded.

Fixes #744
lbochenek/react-native-windows,lbochenek/react-native-windows,lbochenek/react-native-windows,lbochenek/react-native-windows