Probably a couple hundred at most, and for common programs several dozen.
$ objdump -w -j .text --no-show-raw-insn -d /usr/bin/emacs-gtk | egrep '^ *[0-9]+:' | awk '{print $2}' | sort | uniq | wc -l
130
$ objdump -w -j .text --no-show-raw-insn -d /bin/ls | egrep '^ *[0-9]+:' | awk '{print $2}' | sort | uniq | wc -l
97
$ objdump -w -j .text --no-show-raw-insn -d firefox-bin | egrep '^ *[0-9]+:' | awk '{print $2}' | sort | uniq | wc -l
136I wonder if the numbers would change significantly for gentoo or anything compiled manually that had more knowledge of the CPU specifics?
$ objdump -w -j .text --no-show-raw-insn -d /usr/lib64/firefox/firefox-bin | egrep '^ \*[0-9]+:' | awk '{print $2}' | sort | uniq | wc -l
134