(_MAXLDBL, _NMAXLDBL):

(_MAXLDBL, _NMAXLDBL):
Define to work around hpux 7 <math.h> problem.
(<math.h>): Include.
(<float.h>, <stdlib.h>): Include if STDC_HEADERS.
(FLT_RADIX, DBL_MANT_DIG, DBL_DIG): Default to IEEE values.
(DOUBLE_DIGITS_BOUND): New macro.
(float_to_string): By default, generate the fewest number of digits
that represent the floating point value exactly.