Fix nullish coalescing parenthesis with mixed logical operators (#6863)
* Fix nullish coalescing with mixed logical operators parenthesis
Mixing nullish coalescing (`??`) with the other logical operators (`&&` and `||`) requires parenthesis to disambiguate the inteded short circuiting. Without it, it's a `SyntaxError`. Earlier drafts of the spec allowed mixing, but it was disallowed when we reached Stage 3.
See https://v8.dev/features/nullish-coalescing#mixing-and-matching-operators
* Update changelog
* Fixes and cleanup
* Update changelog