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

[iains at gcc dot gnu.org]

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

--- Comment #50 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Dominique d'Humieres from comment #49)
> The patch at https://gcc.gnu.org/ml/gcc-patches/2017-09/msg00045.html is
> still needed after revision r252914 (fix for pr81361).

Yes, that's expected at present.
a. there's evidently some more EH breakage caused by the reorder-and-partition
(see 81733)
b. the libgcc unwinder seems to have some issues even on systems that should
support it
c. we need to do some checking on the availability of the kernel call to fetch
the FDEs and setup the specs accordingly.

 -static-libstdc++ is a workaround (actually, all it's really doing is
overriding the -static-libgcc).

IMO we need to get to the bottom of the various breakages, and preferably fix
them properly - rather than applying a band-aid patch to place libSystem ahead
of libgcc_eh.