I was trying to manually compile some code as 64-bit, but when I pass the -m64 flag to WinObjC clang, it fails with the following error:

failed to load c2 (file not found)

It seems that the MSVC 64-bit backend is missing. However, the rest of my project is also marked as 64-bit (using the MSBuild $(Platform) variable), and compiles just fine. What is going on here? Is there another flag I need to pass to Clang to get it to compile correctly as 64-bit?