[Bug libstdc++/89464] shared_ptr_base.h: error: '__tag' was not declared in this scope (gcc-8.3.0 regression?)

[gcc at nmacleod dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89464

--- Comment #5 from Milhouse <gcc at nmacleod dot com> ---
Thanks very much for digging into this so quickly and identifying the cause,
I'll feed it back to the add-on author.