the imlib-1.9.14 ebuild fails under gcc-3.1 apparently due to the new handling of crappity include file ordering... adding --includedir="" to the configure line in the ebuild fixes the problem.
it has been pointed out to me by Rufiao Valhacouto <rufiao@gmx.net> who this bug doesn't like that the make line also needs includedir=${D}/usr/include in order for this to not suck.
it's also needed to set includedir=${D}/usr/include in the make line of the src_install() function to prevent the header files to install in /
fixed in portage -- thanks for this nice catch!