Is clang/clang++ (not clang-cl) practical for windows development?

I’m trying to build my project with clang on windows and I thought I’d try doing it without clang-cl. One thing that jumps out to me is that for a lot of my third party dependencies which I build from source they build fine with clang-cl but not with clang/clang++. The problems always seem to come down to them assuming a Linux OS. Boost will try to make static libraries with ar or glib will expect ssize_t. When I use clang-cl they handle all the Windows differences fine.

I thought it might make cross platform builds easier if I used the same compiler interface on Windows as I use everywhere else but it seems like the whole world just uses clang-cl.