This really weird. Not when it was commented out, but my guess is it is commented out since the beginning:
The part of code is for MacOS X, X11 subsystem. Macs always have CPUs that support MMX/SSE/SSE2, so there is no point to call assembler to find out... so all assembly code is #ifdefed out... I doubt that adding some back is the cause of -fPIC problems...