[Bug target/63610] Fixing the libtool bug for Yosemite (darwin14)

[fxcoudert at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63610

--- Comment #15 from Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> ---
(In reply to howarth from comment #14)
> You aren't seeing regressions because you're not setting
> MACOSX_DEPLOYMENT_TARGET  during the gcc build.

Oh, so that's it! Thanks for puzzling it out.

I'll ask RM for permission to backport to all active branches (4.8 and 4.9).
Before I do that, can you confirm that the patch works as you expect on trunk,
with MACOSX_DEPLOYMENT_TARGET set? Just to be extra sure.