[Refactor] Unconditionally enable the workaround for floating point
functions that don't respect the processor's FTZ mode.

// Unfortunatey, on some x86-64 platforms (CentOS 6.5) certain
// floating point operations (trunc and ceil) are implemented in
// software as a series of bit operations rather than using the
// appropriate SSE instruction. Manipulating floating point values
// with bitwise operations bypasses the flush to zero mode. Since
// there is no easy way to check whether these operations are
// implemented in hardware or software, the FTZ workaround is enabled
// unconditionally. It might be possible to have CMAKE detect whether
// various floating point operations respect the processor's FTZ mode
// and selectively enable the workaround, but it seems like too much
// work to avoid a single floating point add on platforms with good
// libraries.