dillon1000/react

Adjust scope ranges to block boundaries

Visits the HIR as a tree and updates mutable ranges to ensure their range end is 
aligned with the block in which the scope is declared: 

```javascript 

function foo(cond, a) { 

⌵ original scope 

⌵ expanded scope 

const x = [];    ⌝    ⌝ 

if (cond) {      ⎮    ⎮ 

...            ⎮    ⎮ 

x.push(a);     ⌟    ⎮ 

...                 ⎮ 

}                     ⎮ 

...                   ⌟ 

} 

``` 

The implementation tracks the block in which each scope "starts" (first 
instruction with an operand in that scope), and then finds the first instruction 
at that block (or a parent) which is after the scope's end.