dillon1000/react

[compiler] Validate against locals being reassigned after render

Adds a pass which validates that local variables are not reassigned by functions which may be called after render. This is a straightforward forward data-flow analysis, where we:
1. Build up a mapping of context variables in the outer component/hook
2. Find ObjectMethod/FunctionExpressions which may reassign those context variables
3. Propagate aliases of those functions via StoreLocal/LoadLocal
4. Disallow passing those functions with a Freeze effect. This includes JSX arguments, hook arguments, hook return types, etc.

Conceptually, a function that reassigns a local is inherently mutable. Frozen functions must be side-effect free, so these two categories are incompatible and we can use the freeze effect to find all instances of where such functions are disallowed rather than special-casing eg hook calls and JSX.

ghstack-source-id: c2b22e3d62a1ab490a6a2150e28b934b9dc8676b
Pull Request resolved: https://github.com/facebook/react/pull/30107