sdcc doc build fails with ghostscript 9.07 on Slackware-current (14.0+).
When running configure for sdcc, pdfopt is not present. Pdfopt was removed from ghostscript and is considered depreciated as of 9.0 series. The attached patch for sdcc/doc/Makefile.in and using the shell command 'export PDFOPT=/usr/bin/gs' corrects the problem. I don't know if my corrections are what is wanted for the documentation output though; So, please check over.