dillon1000/react

Replace InferReactiveIdentifiers w new inference

This PR adds one remaining feature to InferReactivePlaces: tracking indirections 
like LoadLocal, PropertyLoad, and similar. Consider something like: 

``` 

// INPUT 

x.push(reactiveValue); 

// HIR 

t0 = LoadLocal 'x' 

t1 = PropertyLoad t0, 'push' 

t2 = LoadLocal 'reactiveValue' // reactive 

t3 = CallExpression mutate t0 . read t1 ( read t2 ) 

``` 

Because a reactive value (`t2`) flows into `t0`, we want to record t0 as 
reactive as well. But that's just the temporary for `LoadLocal 'x'` - what's 
really happening is that from this point, `x` is reactive. 
InferReactiveIdentifiers tracked this, and now that logic is ported into 
InferReactivePlaces as well. That lets us remove all the actual inference from 
InferReactiveIdentifiers.