Components that use children get their children set to nil after any rerenders

[fewkz]

The faulty code is

froact/froact.lua

Lines 174 to 176 in c9790a0

	local children = props[roact.Children]
	props[roact.Children] = nil
	return body(props, hooks, if children then children else blankChildren)

It sets the children to be blank after the first render, which is bad. We can fix this by removing the line that sets the props[roact.Children] to nil, but we don't really want children to be in props. Haven't quite figured out a better solution yet.
For now, to fix, you have to do this following code: local children = hooks.useMemo(function() return children end, {props}), since the children will get set correct whenever props change.

[fewkz]

we could store the children in a table that's weak on props, as a sort of weak cache so that we can recover the children on subsequent renders