Add _fpclassifyf and _isnormalf

[ZERICO2005]

Added the _fpclassifyf function and the fpclassify macro along with its macro constants. Also added _isnormalf

#define FP_NORMAL    0x1
#define FP_ZERO      0x2
#define FP_SUBNORMAL (FP_NORMAL | FP_ZERO)     /* 0x3 */
#define FP_INFINITE  0x4
#define FP_NAN       (FP_NORMAL | FP_INFINITE) /* 0x5 */