The complication is that `Carbon.h` also defines its own`Collection`
type, which is visible in this file as a forward declaration in
`UI_interface_icons.h`. To fix that, move the code that needs to
include platform specific includes to a separate file that includes
fewer Blender headers.
See #103343
Pull Request: https://projects.blender.org/blender/blender/pulls/110731
97769581f5