[Fresh] Always reset useMemoCache on Fast Refresh

[gaearon]

Stacked on #30662.

Alternative to #30663 and #30677.

During a Fast Refresh, we always want to evict the memo cache, same as we do with normal useMemo. The mechanism used by useMemo and other Hooks is this module-level variable:

react/packages/react-reconciler/src/ReactFiberHooks.js

Lines 304 to 307 in fca5d65

	// In DEV, this tracks whether currently rendering component needs to ignore
	// the dependencies for Hooks that need them (e.g. useEffect or useMemo).
	// When true, such Hooks will always be "remounted". Only used during hot reload.
	let ignorePreviousDependencies: boolean = false;

which has DEV-only behavior as if the dependencies are always different:

react/packages/react-reconciler/src/ReactFiberHooks.js

Lines 451 to 460 in fca5d65

	function areHookInputsEqual(
	nextDeps: Array<mixed>,
	prevDeps: Array<mixed> | null,
	): boolean {
	if (__DEV__) {
	if (ignorePreviousDependencies) {
	// Only true when this component is being hot reloaded.
	return false;
	}
	}

The useMemoCache Hook doesn't use a dependency array but conceptually I think we want the same behavior.

Test Plan

The test passes.

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Name	Status	Preview	Comments	Updated (UTC)
react-compiler-playground	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Aug 14, 2024 9:51pm

[react-sizebot]

Comparing: d9eb154...60ed96b

Critical size changes

Includes critical production bundles, as well as any change greater than 2%:

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
oss-stable/react-dom/cjs/react-dom.production.js	=	6.68 kB	6.68 kB	=	1.82 kB	1.82 kB
oss-stable/react-dom/cjs/react-dom-client.production.js	=	500.37 kB	500.37 kB	=	89.80 kB	89.80 kB
oss-experimental/react-dom/cjs/react-dom.production.js	=	6.69 kB	6.69 kB	=	1.83 kB	1.83 kB
oss-experimental/react-dom/cjs/react-dom-client.production.js	=	507.50 kB	507.50 kB	=	90.96 kB	90.96 kB
facebook-www/ReactDOM-prod.classic.js	=	595.24 kB	595.24 kB	=	105.55 kB	105.55 kB
facebook-www/ReactDOM-prod.modern.js	=	571.54 kB	571.54 kB	=	101.75 kB	101.75 kB

Significant size changes

Includes any change greater than 0.2%:

(No significant changes)

Generated by 🚫 dangerJS against 4d86c1b

[josephsavona]

amazing!

[poteto]

ahh nice, yeah this makes sense if we already had this infra from before