Deprecate b-prefix for strings

All,

The b string prefix and the (binary) cast were both introduced in
PHP 5.2.1 for forward compatibility with PHP 6.

In 2016, there was an RFC [1] targeting PHP 7.x to deprecate both, which
was declined.

Since then, the (binary) type cast has now been deprecated in PHP
8.5.0 [2], but as far as I can see, the b-prefix for strings is still
supported.

I can't remember ever coming across this in the wild, so I wonder if it
might be a good idea to deprecate the b-prefix now as well.

I'll happily create an RFC for this if the you all think it's a good idea.

Opinions ?

Smile,
Juliette

1: https://wiki.php.net/rfc/binary_string_deprecation
2:
https://wiki.php.net/rfc/deprecations_php_8_5#deprecate_non-standard_cast_names