It gets better. I reverted to the old llvm-* from my not-recently-updated rsync mirror, and X now starts, but vmtools doesn't work, maybe because of this:
[ 26.013] (II) Loading /usr/local/lib/xorg/modules/drivers/vmware_drv.so
[ 26.013] (EE) Failed to load /usr/local/lib/xorg/modules/drivers/vmware_drv.so: libLLVM-4.0.so: cannot open shared object file: No such file or directory
Whaaaat? So, checking vmware_drv.so with ldd gives:
linux-vdso.so.1 (0x00007ffce01b6000)
libxatracker.so.2 => /usr/local/lib/libxatracker.so.2 (0x00007f7ecb4ce000)
libcrypto.so.1.0.0 => /usr/local/lib/libcrypto.so.1.0.0 (0x00007f7ecb0c6000)
libpthread.so.0 => /lib/libpthread.so.0 (0x00007f7ecaeab000)
libdl.so.2 => /lib/libdl.so.2 (0x00007f7ecaca8000)
libexpat.so.1 => /usr/local/lib/libexpat.so.1 (0x00007f7ecaa87000)
libdrm_intel.so.1 => /usr/local/lib/libdrm_intel.so.1 (0x00007f7eca865000)
libpciaccess.so.0 => /usr/local/lib/libpciaccess.so.0 (0x00007f7eca65e000)
libdrm_nouveau.so.2 => /usr/local/lib/libdrm_nouveau.so.2 (0x00007f7eca457000)
libdrm.so.2 => /usr/local/lib/libdrm.so.2 (0x00007f7eca249000)
libLLVM-3.9.so => /usr/local/lib/libLLVM-3.9.so (0x00007f7ec86aa000)
libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x00007f7ec8371000)
libm.so.6 => /lib/libm.so.6 (0x00007f7ec807c000)
libc.so.6 => /lib/libc.so.6 (0x00007f7ec7d16000)
libz.so.1 => /usr/lib/libz.so.1 (0x00007f7ec7b04000)
libLLVM-4.0.so => not found
libgcc_s.so.1 => /usr/lib/libgcc_s.so.1 (0x00007f7ec78f2000)
/lib/ld-linux-x86-64.so.2 (0x000056201fa1f000)
libffi.so.6 => /usr/local/lib/../lib/libffi.so.6 (0x00007f7ec76e9000)
librt.so.1 => /lib/librt.so.1 (0x00007f7ec74e2000)
libtinfo.so.6 => /usr/local/lib/../lib/libtinfo.so.6 (0x00007f7ec72bc000)
It now requires libLLVM 3.9 and 4.0? Heads up when you rebuild it.