[RFC] Deprecate left-associative ternary operator

Hi internals, Inspired by Bob's recent RFC for concat precedence, I'd like to propose a deprecation and removal of the left-associative behavior of ternaries. Instead, explicit parentheses should be used: https://wiki.php.net/rfc/ternary_associativity This RFC makes nested ternaries without disambiguating parentheses an error in PHP 8 -- we might want to consider making them right-associative instead, which is both useful and matches the behavior of other languages. Regards, Nikita