[Bug sanitizer/78267] [7 Regression] libsanitizer breaks bootstrap on x86_64-apple-darwin16 at r241977

["iains at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78267

--- Comment #49 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to ro@CeBiTec.Uni-Bielefeld.DE from comment #48)
> > --- Comment #47 from Maxim Ostapenko <m.ostapenko at samsung dot com> ---
> [...]
> > Rainer, sorry for a dumb question: are you going to commit your fix for
> > darwin_availabilityinternal part? Or should I just apply a patch from comment
> > #15?
> > I've completely messed in this discussion thus I don't understand clearly what
> > should I do now.
> 
> Not a dumb question at all: I'm somewhat lost in this PR myself.  I
> guess we need to make a concerted effort to test the combo of the
> darwin_availabilityinternal fix and the __BLOCKS__ guard in
> sanitizer_mac.cc on at last Darwin 16, 15 and 14.  I can do 16 myself,
> but probably not before Friday.

I can do darwin14 (I built 242408 last night with the patches-in-progress +
__BLOCKS__) but that's a little bit more than the minimum
(darwin_availabilityinternal + __BLOCKS__)

choice 1.  Rainer splits out the minimum (darwin_availabilityinternal) from his
original patch and we put that together with the __BLOCKS__ one.

choice 2. Rainer posts his current patch (which is at least correcting some of
the problems, even if not complete) and we apply that together with the
__BLOCKS__ one.