frexp, tests: work around ICC bug with -zero * m4/frexp.m4 (gl_FUNC_FREXP_WORKS): Compute -0.0 in a way that works with more compilers. * tests/minus-zero.h: New file. * modules/ceilf-tests (Files): Include it. * modules/ceill-tests (Files): Likewise. * modules/floorf-tests (Files): Likewise. * modules/floorl-tests (Files): Likewise. * modules/frexp-nolibm-tests (Files): Likewise. * modules/frexp-tests (Files): Likewise. * modules/frexpl-nolibm-tests (Files): Likewise. * modules/frexpl-tests (Files): Likewise. * modules/isnan-tests (Files): Likewise. * modules/isnand-nolibm-tests (Files): Likewise. * modules/isnand-tests (Files): Likewise. * modules/isnanf-nolibm-tests (Files): Likewise. * modules/isnanf-tests (Files): Likewise. * modules/isnanl-nolibm-tests (Files): Likewise. * modules/isnanl-tests (Files): Likewise. * modules/round-tests (Files): Likewise. * modules/roundf-tests (Files): Likewise. * modules/roundl-tests (Files): Likewise. * modules/ldexpl-tests (Files): Likewise. * modules/signbit-tests (Files): Likewise. * modules/snprintf-posix-tests (Files): Likewise. * modules/sprintf-posix-tests (Files): Likewise. * modules/strtod-tests (Files): Likewise. * modules/trunc-tests (Files): Likewise. * modules/truncf-tests (Files): Likewise. * modules/truncl-tests (Files): Likewise. * modules/vsnprintf-posix-tests (Files): Likewise. * modules/vsprintf-posix-tests (Files): Likewise. * modules/vasnprintf-posix-tests (Files): Likewise. * modules/vasprintf-posix-tests (Files): Likewise. * tests/test-ceilf1.c (main): Use it. * tests/test-ceill.c (main): Likewise. * tests/test-floorf1.c (main): Likewise. * tests/test-floorl.c (main): Likewise. * tests/test-frexp.c (main): Likewise. * tests/test-frexpl.c (main): Likewise. * tests/test-isnan.c (main): Likewise. * tests/test-isnand.h (main): Likewise. * tests/test-isnanf.h (main): Likewise. * tests/test-isnanl.h (main): Likewise. * tests/test-ldexpl.c (main): Likewise. * tests/test-round.c (main): Likewise. * tests/test-roundf.c (main): Likewise. * tests/test-roundl.c (main): Likewise. * tests/test-signbit.c (test_signbitf, test_signbitd) (test_signbitl): Likewise. * tests/test-snprintf-posix.h (test_function): Likewise. * tests/test-sprintf-posix.h (test_function): Likewise. * tests/test-strtod.c (main): Likewise. * tests/test-trunc1.c (main): Likewise. * tests/test-truncf1.c (main): Likewise. * tests/test-truncl.c (main): Likewise. Signed-off-by: Eric Blake <eblake@redhat.com>