[Bug libgomp/91694] configure.ac does not correctly check for gethostname

[rishi@extreme-scale.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91694

Rishi Khan <rishi@extreme-scale.com> changed:

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--- Comment #1 from Rishi Khan <rishi@extreme-scale.com> ---
To clarify further, configure.ac instructs to see if the program can compile
and produce a *.o file. This works, with a warning but not error returned.
However, a system that does not have gethostname will not link properly. That
is why I think it should be AC_LINK_IFELSE instead of AC_COMPILE_IFELSE. There
are a few other AC_COMPILE_IFELSE that should also be looked at. I think they
may suffer the same problem.