[Bug c++/66934] Compiler accepting ill-formed program with extern variable declarations and using-declaration

[anders.granlund.0 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66934

--- Comment #2 from Anders Granlund <anders.granlund.0 at gmail dot com> ---
(In reply to Jonathan Wakely from comment #1)
> I think we could combine most of your reports into one or two PRs since
> they're all related and fixing them one by one would probably not be very
> efficient.

What is a PR?