[commit] Fix for nested optional chaining within other value blocks

Fixes a longstanding issue where we didn't support code like `useFoo(value?.bar(), value?.bar()) ?? {}` - we would attempt to construct a ReactiveFunction, recursively processing the blocks, but the inner optional `value?.bar()` wouldn't match with what the outer optional was expecting to find. It's a one-line fix!

Note: memoization in the examples is not ideal, but i've confirmed that it is not strictly related to the optional issue.