[Bug libgomp/64635] darwin produces libgomp-plugin-host_nonshm.1.dylib but tries to load libgomp-plugin-host_nonshm.so.1

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64635

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Better add config/darwin/ and some header to it that defines SONAME_SUFFIX(n),
where it would be ".so." #n in config/posix/ version of the header and
"." #n ".dylib" in the config/darwin/ version of the header.