This doesn’t really look to have anything to do with Clang/LLVM in particular.
Instead, this looks more like one of several things:
Out of disk space. Did you check the size of the files that it’s complaining about? Are they zero-sized?
Your build is partly broken – Start again with a clean build. MSVC has a tendency of not cleaning up partially written output files when a build fails with a compiler/linker crash.
Your MSVC installation is broken – Re-installation time
I would also recommend using the ninja build tool over nmake. ninja is better behaved. It cleans up output files after failed invocations and will give you more parallelism. It’s a very small executable, so it’s not a huge dependency.