[Bug target/68945] enable libcilkrts on SPARC

[stefan.teleman at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68945

--- Comment #7 from Stefan Teleman <stefan.teleman at oracle dot com> ---
> Since Stefan hasn't followed up and I'm currently looking at other
> libcilkrts issues anyway, I'm taking over from here.

Had every intention to follow-up with a cleaned-up patch, but did not find
the time to re-do the patch.

I will look into the SIGBUS crashes on SPARC64 and see what i come up
with.