[babel 8] Require throw expression to be wrapped in parentheses

[nicolo-ribaudo]

Q	A
Fixed Issues?	Fixes #1, Fixes #2
Patch: Bug Fix?
Major: Breaking Change?
Minor: New Feature?
Tests Added + Pass?	Yes
Documentation PR Link
Any Dependency Changes?
License	MIT

There has been a lot of discussion in TC39 on what the precedence of throw expressions should be, and on when to require parentheses. That discussion is not settled yet, but you can read it at https://github.com/tc39/notes/blob/main/meetings/2023-09/september-26.md#throw-expressions-for-stage-3 + https://github.com/tc39/notes/blob/main/meetings/2023-09/september-28.md#throw-expression-continued (and slides at https://onedrive.live.com/view.aspx?resid=934F1675ED4C1638%21297369&authkey=!APFRcEQ8M_eUfds).

This PR implements one of the alternative (i.e. only allow throw expressions when directly inside parentheses), and I'm opening this as a draft just to avoid loosing it in old branches on my PC.

[babel-bot]

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/56108/