FreeBSD and NetBSD both use derivates of Sun's math library. On FreeBSD,
it's been put into lib/msun, on NetBSD it is under lib/libm. Since
DragonFly misses a lot of the changes which went into both and I
consider the NetBSD version cleaner, switch to that.
Biggest difference to NetBSD is the omission of wrappers for non-IEEE757
floating point support. There's no point in supporting anything but IEEE
757 and that saves at least a function call per math entry point.
Addtionally, important the fpclassify, isinf, isnan and signbit
functions into libc as required for C99.
Remove the support for non-POSIX operation. matherr is pointless and
wasn't really supported anyway.
- [DB] lib/libm/arch/i386/e_log10.S