Code directly adapted from libSDL_image, trying to keep changes to a minimum to make sure it's easy to diff against the original, so changes there can be applied here too (some ugly defines to map SDL things to the corresponding DevIL feature).
I've replaced the (unused) IL_LBM enum with IL_ILBM
I'm using linux, and have done some minor fiddling to add the new il.ilbm.c file to the automake/autoconf setup, and to add a configure option to disable ilbm support.
I've not touched any of the other project files/build system configs.
It loads all my old Amiga graphics files without problem (yay!).
It loads "Test Images/HAM/crater.ham", although I haven't checked to see it looks OK yet (my test app rejects any images without a palette).
It doesn't load "Test Images/ILBM/rgb8c.ilbm". I couldn't get this to load in Deluxe Paint either (tried dpaint 3 and dpaint 4.1, running under the UAE amiga emulator).
I think this is an AGA image (AGA=later-model amiga, with higher colour depth hardware). I will investigate if I get some time.
I can be contacted at ben at scumways.com.