Skip a test that fails on x86_64 with GCC 16

sleef.spec

@@ -278,6 +278,18 @@ then
 fi
 %endif
 
+%ifarch %{x86_64}
+%if %{undefined fc43} && %{undefined fc42} && %{undefined el10}
+# At least one test within this executable fails since GCC 16 landed in Fedora
+# 44. It’s not very easy to tell exactly what is going wrong, and upstream is
+# not likely to be interested since (as determined by bisection) the failure
+# was resolved upstream by the removal of no-FMA helpers in
+# https://github.com/shibatch/sleef/pull/685. Let’s just skip this while we
+# await the next upstream release.
+skips="${skips}|tester4ypurec_scalar"
+%endif
+%endif
+
 skips="${skips})$"
 
 %ctest --exclude-regex "${skips}" --extra-verbose