Support for MSVC compiler: Avoid division by a literal 0. * lib/math.in.h (NAN): Define through a function call also on MSVC. * m4/frexp.m4 (gl_FUNC_FREXP_WORKS): Divide by 'zero' instead of 0.0. * m4/printf.m4 (gl_PRINTF_INFINITE, gl_PRINTF_DIRECTIVE_A, gl_PRINTF_DIRECTIVE_F, gl_PRINTF_FLAG_ZERO): Likewise. (gl_PRINTF_INFINITE_LONG_DOUBLE): Divide by 'zeroL' instead of 0.0L. * tests/infinity.h: New file. * tests/nan.h (NaNf, NaNd, NaNl): Define through a function call also on MSVC. * tests/test-ceilf1.c: Include infinity.h. (main): Use Infinityf. * tests/test-ceil1.c: Include infinity.h. (main): Use Infinityd. * tests/test-ceill.c: Include infinity.h. (main): Use Infinityl. * tests/test-dprintf-posix.c: Include infinity.h. (test_function): Use Infinityd. * tests/test-floorf1.c: Include infinity.h. (main): Use Infinityf. * tests/test-floor1.c: Include infinity.h. (main): Use Infinityd. * tests/test-floorl.c: Include infinity.h. (main): Use Infinityl. * tests/test-fprintf-posix.c: Include infinity.h. (test_function): Use Infinityd. * tests/test-frexp.c: Include infinity.h. (main): Use Infinityd. * tests/test-frexpl.c: Include infinity.h. (main): Use Infinityl. * tests/test-isfinite.c: Include infinity.h. (test_isfinitef): Use Infinityf. (test_isfinited): Use Infinityd. (test_isfinitel): Use Infinityl. * tests/test-isinf.c: Include infinity.h. (test_isinff): Use Infinityf. (test_isinfd): Use Infinityd. (test_isinfl): Use Infinityl. * tests/test-isnan.c: Include infinity.h. (test_float): Use Infinityf. (test_double): Use Infinityd. (test_long_double): Use Infinityl. * tests/test-isnanf.h: Include infinity.h. (main): Use Infinityf. * tests/test-isnand.h: Include infinity.h. (main): Use Infinityd. * tests/test-isnanl.h: Include infinity.h. (main): Use Infinityl. * tests/test-ldexpl.c: Include infinity.h. (main): Use Infinityl. * tests/test-printf-posix.h: Include infinity.h. (test_function): Use Infinityd. * tests/test-roundf1.c: Include infinity.h. (main): Use Infinityf. * tests/test-round1.c: Include infinity.h. (main): Use Infinityd. * tests/test-roundl.c: Include infinity.h. (main): Use Infinityl. * tests/test-signbit.c: Include infinity.h. (test_signbitf): Use Infinityf. (test_signbitd): Use Infinityd. (test_signbitl): Use Infinityl. * tests/test-snprintf-posix.h: Include infinity.h. (test_function): Use Infinityd, Infinityl. * tests/test-sprintf-posix.h: Include infinity.h. (test_function): Use Infinityd, Infinityl. * tests/test-truncf1.c: Include infinity.h. (main): Use Infinityf. * tests/test-trunc1.c: Include infinity.h. (main): Use Infinityd. * tests/test-truncl.c: Include infinity.h. (main): Use Infinityl. * tests/test-vasnprintf-posix.c: Include infinity.h. (test_function): Use Infinityd, Infinityl. * tests/test-vasprintf-posix.c: Include infinity.h. (test_function): Use Infinityd, Infinityl. * modules/ceilf-tests (Files): Add tests/infinity.h. * modules/ceil-tests (Files): Likewise. * modules/ceill-tests (Files): Likewise. * modules/dprintf-posix-tests (Files): Likewise. * modules/floorf-tests (Files): Likewise. * modules/floor-tests (Files): Likewise. * modules/floorl-tests (Files): Likewise. * modules/fprintf-posix-tests (Files): Likewise. * modules/frexp-tests (Files): Likewise. * modules/frexp-nolibm-tests (Files): Likewise. * modules/frexpl-tests (Files): Likewise. * modules/frexpl-nolibm-tests (Files): Likewise. * modules/isfinite-tests (Files): Likewise. * modules/isinf-tests (Files): Likewise. * modules/isnan-tests (Files): Likewise. * modules/isnanf-tests (Files): Likewise. * modules/isnanf-nolibm-tests (Files): Likewise. * modules/isnand-tests (Files): Likewise. * modules/isnand-nolibm-tests (Files): Likewise. * modules/isnanl-tests (Files): Likewise. * modules/isnanl-nolibm-tests (Files): Likewise. * modules/ldexpl-tests (Files): Likewise. * modules/printf-posix-tests (Files): Likewise. * modules/roundf-tests (Files): Likewise. * modules/round-tests (Files): Likewise. * modules/roundl-tests (Files): Likewise. * modules/signbit-tests (Files): Likewise. * modules/snprintf-posix-tests (Files): Likewise. * modules/sprintf-posix-tests (Files): Likewise. * modules/truncf-tests (Files): Likewise. * modules/trunc-tests (Files): Likewise. * modules/truncl-tests (Files): Likewise. * modules/vasnprintf-posix-tests (Files): Likewise. * modules/vasprintf-posix-tests (Files): Likewise. * modules/vdprintf-posix-tests (Files): Likewise. * modules/vfprintf-posix-tests (Files): Likewise. * modules/vprintf-posix-tests (Files): Likewise. * modules/vsnprintf-posix-tests (Files): Likewise. * modules/vsprintf-posix-tests (Files): Likewise. * modules/xprintf-posix-tests (Files): Likewise.