(FLOAT_CHECK_ERRNO): Define unless NO_FLOAT_CHECK_ERRNO.

(FLOAT_CHECK_ERRNO): Define unless NO_FLOAT_CHECK_ERRNO.

Changes from Lucid:
(HAVE_MATHERR, FLOAT_CHECK_ERRNO, FLOAT_CATCH_SIGILL): New parm macros.
(FLOAT_CHECK_DOMAIN, HAVE_RINT): New parm macros.
(HAVE_INVERSE_HYPERBOLIC, HAVE_CBRT): New parm macros.
[!HAVE_RINT]: Define rint as macro.
(IN_FLOAT): Major rewrite; several alternate versions.
(IN_FLOAT2): New macro.
(arith_error, range_error, domain_error, domain_error2): New macros.
(Facos, Fasin, Fatan, Fcos, Fsin, Ftan, Fexp, Fexpt, Flog): Changed.
(Flog10, Fsqrt, Fabs, Ffloat, Flogb): Changed.
(Ffloor, Fceiling, Fround, Ftruncate): Changed.
(Fcube_root): Renamed from Fcbrt.
(matherr): New function.
(float_error): Only if FLOAT_CATCH_SIGILL.