* doc/posix-headers/math.texi: Mention some FreeBSD and AIX bugs.
* lib/math.in.h (INFINITY): New macro.
(NAN): Replace also on FreeBSD < 8 and AIX. Use __builtin_nanf where
available.
(HUGE_VALF): Replace also on FreeBSD < 6. Use __builtin_inff where
available.
(HUGE_VAL): Replace also on FreeBSD < 6. Use __builtin_inf where
available.
(HUGE_VALL): Replace also on FreeBSD < 6. Use __builtin_infl where
available.
* tests/test-math.c: Check that INFINITY, NAN, HUGE_VALF, HUGE_VAL,
HUGE_VALL are constant expressions.
(main): Check the type of INFINITY and NAN.