Log Message:
devel/php-memcache: update to 8.0

Update php-memcache to 8.0.  This is now for php80.

8.0.0 (2020-12-06)

- Version 8.x support PHP 8.x
- Version 4.x supports PHP 7.0-7.4.
- Version 4.x is considered to be stable for production usage.
- Support for PHP 5.x has been removed, please use memcache extension
  ver. 3.x
- Special thanks to Frantisek Drojak - thesource93 (github) and Zaffy
  (github) for making this happen