#324 float classification macros

[Philipp Klaus Krause]

The C99 float classification macros that should be in math.h are missing:

int fpclassify(x);
int isfinite(x);
int isnormal(x);
int isnan(x);
int isinf(x);

Giving this slightly above-average priority, since these macros would help in fixing some bugs in the runtime library.

Philipp

[Benedikt Freisen]

The code is basically there, but has not found its way into the repository, yet.