[Bug target/97865] libtool needs to be updated for Darwin20.

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97865

--- Comment #24 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Iain Sandoe from comment #22)
> (In reply to Iain Sandoe from comment #19)
> > (In reply to Jürgen Reuter from comment #16)
> > > (In reply to Iain Sandoe from comment #15)
> > > > (In reply to Jürgen Reuter from comment #14)
> > 
> > 
> > > clang: error: argument unused during compilation: '-no-pie'
> > > [-Werror,-Wunused-command-line-argument]
> > > make[2]: [lto-dump] Error 1 (ignored)
> > 
> > I saw this issue on i686-darwin9 when trying the branch, it seems that the
> > configuration is using the built compiler for this test - but then using the
> > build system c++ for the install ... it's not obvious that my changes could
> > cause this - I am investigating (it's not a problem if the bootstrap / build
> > system c++ support no-pie, which is the case for the gcc-7.5 bootstrap).
> 
> I see this error with r11-5147 and no patches applied (so it's pre-existing
> - somewhere between r11-5028 and r11-5147).
> 
> e.g. i686-darwin9:
> 
> make install gives .. 
> g++: error: unrecognized command line option '-no-pie'
> make[2]: *** [gnat1] Error 1
> make[1]: *** [install-gcc] Error 2
> make: *** [install] Error 2
> 
> x86_64-darwin20 (no configure changes) 
> 
> clang: error: argument unused during compilation: '-no-pie'
> [-Werror,-Wunused-command-line-argument]
> make[2]: *** [cc1plus] Error 1
> make[1]: *** [install-gcc] Error 2
> make: *** [install] Error 2

looks like this was caused by
 https://gcc.gnu.org/pipermail/gcc-cvs/2020-November/337375.html

and is fixed by
https://gcc.gnu.org/pipermail/gcc-patches/2020-November/559605.html

(but more testing needed)