[Bug target/104189] enable 64-bit compare-and-swap on SPARC/Linux with V9

[glaubitz at physik dot fu-berlin.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104189

--- Comment #6 from John Paul Adrian Glaubitz <glaubitz at physik dot fu-berlin.de> ---
(In reply to Eric Botcazou from comment #5)
> > The function init_sparc64_elf_hwcap(void) [1] unconditionally enables it
> > with:
> > 
> > cap |= (AV_SPARC_MUL32 | AV_SPARC_DIV32 | AV_SPARC_V8PLUS);
> > 
> > So, I think it should be safe and enable V8+ on sparc64 for 32-bit targets
> > the same way it is done on Solaris.
> 
> OK, thanks, running the testsuite of the modified compiler with -m32 does
> not exhibit anything suspicious either, so I'm going to make the change on
> mainline.

Awesome, thanks! Can we get a backport for gcc-11 as well?