To compile bochs to use this FPU emulator, grab the wm-FPU-emu package from the bochs FTP site, and extract it somewhere. This will create a directory called "math-emu". Supply the path to this directory to the configure command in bochs, by including the option "--enable-fpu=/path/math-emu", where path is wherever you extracted it.
Error reporting needs more work. Though, I have got the paranoia tests to run on Linux running inside of bochs linked with wm-FPU-emu. They ran the same as on a real Linux/Pentium machine.
-Kevin