[Bug c++/87380] Explicit instantations should use weak symbols on darwin

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87380

Iain Sandoe <iains at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-09-21
     Ever confirmed|0                           |1

--- Comment #4 from Iain Sandoe <iains at gcc dot gnu.org> ---
In Darwin dialect...
gcc -v =>
gcc version 9.0.0 20180908 (experimental) [trunk revision 264172] (GCC) 

$ ./gcc/xg++ -Bgcc -shared  lib.cc -o liblib.dylib
$ ./gcc/xg++ -Bgcc main.cc -L. -llib -o t
$ DYLD_LIBRARY_PATH=. ./t
libc++abi.dylib: terminating with uncaught exception of type int
Abort trap: 6