[Bug bootstrap/62077] --with-build-config=bootstrap-lto fails

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62077

--- Comment #68 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Sven C. Dack from comment #67)
> (In reply to Richard Biener from comment #66)
> > The issue re-appears with GCC 6, the workaround doing
> > --enable-stage1-checking=release still works.
> > 
> > Note that the comparison we do with LTO bootstrap is quite pointless as we
> > only compile the internal IL at LTO streaming time but not the final result
> > of optimization.  For that we'd need to compare cc1, cc1plus, etc. itself.
> To call it pointless is as dismissive of the effort as saying you'd be
> willing to accept any indeterministic behaviour, including magic, into
> computer science as long as it produces great software. Let's not be this
> lazy.

I'm calling it pointless to motivate adding comparison of the optimized
binaries themselves.  I'm not arguing to remove bootstrap comparison
completely - but maybe to remove LTO IL comparison if we got optimized
binary comparison in exchange.