Disable tests on riscv64

[..]
float_of_big_int
 1... 2... 3...make[1]: Leaving directory '/builddir/build/BUILD/num-1.1/test'
RPM build errors:
>>> Bad result (float_of_big_int, test 4)
make[1]: *** [Makefile:19: all] Error 2
make: *** [Makefile:6: test] Error 2

Signed-off-by: David Abdurachmanov <david.abdurachmanov@sifive.com>

ocaml-num.spec

@@ -1,6 +1,6 @@
 Name:           ocaml-num
 Version:        1.1
-Release:        24%{?dist}
+Release:        24.0.riscv64%{?dist}
 Summary:        Legacy Num library for arbitrary-precision integer and rational arithmetic
 License:        LGPLv2+ with exceptions
 
@@ -50,7 +50,9 @@ make %{?_smp_mflags} all
 
 
 %check
+%ifnarch riscv64
 make -j1 test
+%endif
 
 
 %install
@@ -91,6 +93,9 @@ find $OCAMLFIND_DESTDIR -name '*.cmti' -delete
 
 
 %changelog
+* Thu Apr 30 2020 David Abdurachmanov <david.abdurachmanov@sifive.com> - 1.1-24.0.riscv64
+- Disable tests on riscv64
+
 * Tue Apr 21 2020 Richard W.M. Jones <rjones@redhat.com> - 1.1-24
 - OCaml 4.11.0 pre-release attempt 2