dillon1000/react

Option to assume hooks follow the rules

Adds a new feature flag which tells the compiler to assume that hooks follow the 
Rules of React. Specifically, the idea that since any hook could be wrapped in a 
giant `useMemo()` call, all arguments to hooks have to be treated as if they're 
owned by React — and therefore become immutable — and that the return value of 
the hook is immutable. 

Our default is to assume that hooks break the rules, but in practice nearly 
every component follows them.