[Fontconfig] How necessary is 'scandir'?

[aixtools]

checking for posix_fadvise in fcntl.h... fcntl.h
checking for scandir... configure: error:
*** No scandir function available.

Background: I am trying to package a recent version of rrdtool - which 
has several dependancies - and fontconfig is one of them.

While the rrdtool says fontconfig-2.4.2 is sufficient (and I have that 
done) I am trying to be as up-to-date as possible with dependancies. 
When I run 'configure' on AIX I get the error above (maybe more will 
follow).

If scandir is a must, then this gets moved to longer-term, if not - 
please suggest the best way to correct this.

Many thanks,
Michael