[Bug libstdc++/124268] `import std` initializer symbol is not shipped in `libstdc++`

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124268

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|15.3                        |17.0

--- Comment #14 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #12)
> Fixed on trunk, but I suppose this would be good to do for 15.3 as well.

Actually, we can't do it for 15.x because it needs new symbols in the DSO and
we can't add those now.

I'll change the Target milestone to 17.0 for now, but I'll try to get it
backported to 16.2 after it's done on trunk.