[Bug target/80556] [8 Regression] bootstrap failure for Ada compiler

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80556

--- Comment #47 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
This PR is "fixed" by applying the patch at
  https://gcc.gnu.org/ml/gcc-patches/2017-09/msg00045.html
on top of revision r251529. However it does not fix pr82141.

> I posted my darwin.h patch at
> https://gcc.gnu.org/ml/gcc-patches/2017-09/msg00045.html
> on 1 September - hasn’t attracted any notice yet.

May be PING for it.