V3 PATCH: #undef some C99 math macros in <cmath>

[Benjamin Kosnik]

a better way to do this would be to disable _USE_GNU so that math.h 
doesn't define the C99 stuff at all. We're going to have to do something 
similar to get long long working correctly. (I'm planing on working on 
that after the backwards stuff gets finished/in)

also, can you please please please. Please. Please put in a testsuite 
regression? 

-benjamin

> + #undef fpclassify
> + #undef isfinite
> + #undef isinf
> + #undef isnan
> + #undef isnormal
> + #undef signbit
> + 
> + #undef isgreater
> + #undef isgreaterequal
> + #undef isless
> + #undef islessequal
> + #undef islessgreater
> + #undef isunordered

in the short term, this is acceptable.

thanks,
benjamin