Yeah, guessing that’s what the library machine type 'x86' conflicts with target machine type 'x64' warnings are on about. It would be easy to check that in the vcxproj files for Windows projects, unlikely they would have built it with anything other than cmake though.
Couple of threads of interest, Hello, there is no 64-bit Debug version under the window and Best DevIL version to use? Should ReSIL be used over DevIL?