[Bug lto/63997] gcc.dg/lto/pr61526 failing on darwin

[fxcoudert at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63997

--- Comment #3 from Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #1)
> The testcase uses -shared at link time which is supposed to build a shared
> object and generate an external (unresolved) reference to _master.

Adding -Wl,-undefined,dynamic_lookup makes it pass. (And the -shared is
correctly passed, as far as I can see.)