[compiler] Fix false positive hook return mutation error

[josephsavona]

This was fun. We previously added the MaybeAlias effect in #33984 in order to describe the semantic that an unknown function call may alias its return value in its result, but that we don't know this for sure. We record mutations through MaybeAlias edges when walking backward in the data flow graph, but downgrade them to conditional mutations. See the original PR for full context.

That change was sufficient for the original case like

const frozen = useContext();
useEffect(() => {
  frozen.method().property = true;
}, [...]);

But it wasn't sufficient for cases where the aliasing occured between operands:

const dispatch = useDispatch();
<div onClick={(e) => {
  dispatch(...e.target.value)
  e.target.value = ...;
}} />

Here we would record a Capture dispatch <- e.target effect. Then during processing of the event.target.value = ... assignment we'd eventually forward from event to dispatch (along a MaybeAlias edge). But in #33984 I missed that this forward walk also has to downgrade to conditional.

In addition to that change, we also have to be a bit more precise about which set of effects we create for alias/capture/maybe-alias. The new logic is a bit clearer, I think:

• If the value is frozen, it's an ImmutableCapture edge
• If the values are mutable, it's a Capture
• If it's a context->context, context->mutable, or mutable->context, count it as MaybeAlias.

[josephsavona]

Fixes #34418

[poteto]

minor nit, should we update the reason or move into description?

Suggested change

	reason: `Expected destination value to already be initialized within this instruction for Alias effect`,
	reason: `Expected destination value to already be initialized within this instruction for ${effect.kind} effect`,

[josephsavona]

Yeah fair. I’m less worried about aggregating invariants since they shouldn’t happen but for consistency, yes!

[poteto]

maybe obvious, but do we need to downgrade as well when traversing backwards?

[josephsavona]

Yup! We already do, it’s a bit further down where we iterate the node.maybeAliases

[josephsavona]

see https://github.com/facebook/react/pull/34424/files#diff-f4a1138501d81ef48b60b2710888fd67f24e6bd756ed34c2218cf8858bcdc4bfR838