Well, turns out I'm a dope.
The pathappend is an environment variable containing a script. Description of setting it up is part of the BLFS 8.0 book.
Code:
pathappend () {
pathremove $1 $2
local PATHVARIABLE=${2:-PATH}
export $PATHVARIABLE="${!PATHVARIABLE:+${!PATHVARIABLE}:}$1"
}
That is placed in the /etc/profile script.