[Bug bootstrap/87030] GCC fails to build with Xcode 10, attempting an impossible multilib build

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87030

--- Comment #3 from Iain Sandoe <iains at gcc dot gnu.org> ---
Just a few notes:

1. I'm not objecting to some kind of automation to switch off the 32b multiline
where the *target* system is >= 10.14/Darwin18 (someone needs to write it,
that's all).

2. Actually, you get the same failure on GNU-Linux if you try to configure
defaults on (for example) an x86_64 system without 32bit libs installed (one
has to add --disable-multilib there, or install 32b libs), so automation is not
the default on Linux.

3. I don't see why GCC should be subject to the vendor's support policy.  As
far as I am concerned, with the right SDK / sysroot available, there's no
reason why a compiler *hosted* on x86-64-Darwin18 shouldn't be able to build
code for i686-darwin10 *target*.