usr/src/lib/clang/libllvmtablegen/../../../contrib/llvm/lib/TableGen/Error.cpp:15:10: fatal error: 'llvm/TableGen/Error.h' file not found, #include "llvm/TableGen/Error.h"

Trying to build buildworld on FreeBSD 10-CURRENT/amd64 with CLANG today
ends up in the following error:

===> lib/clang/libllvmtablegen (obj,depend,all,install)
/usr/obj/usr/src/tmp/usr/src/lib/clang/libllvmtablegen created for
/usr/src/lib/clang/libllvmtablegen
rm -f .depend
CC='clang' mkdep -f .depend -a
-I/usr/obj/usr/src/tmp/legacy/usr/include
/usr/src/lib/clang/libllvmtablegen/../../../contrib/llvm/lib/TableGen/Error.cpp
/usr/src/lib/clang/libllvmtablegen/../../../contrib/llvm/lib/TableGen/Main.cpp
/usr/src/lib/clang/libllvmtablegen/../../../contrib/llvm/lib/TableGen/Record.cpp
/usr/src/lib/clang/libllvmtablegen/../../../contrib/llvm/lib/TableGen/TableGenAction.cpp
/usr/src/lib/clang/libllvmtablegen/../../../contrib/llvm/lib/TableGen/TableGenBackend.cpp
/usr/src/lib/clang/libllvmtablegen/../../../contrib/llvm/lib/TableGen/TGLexer.cpp
/usr/src/lib/clang/libllvmtablegen/../../../contrib/llvm/lib/TableGen/TGParser.cpp

/usr/src/lib/clang/libllvmtablegen/../../../contrib/llvm/lib/TableGen/Error.cpp:15:10:
fatal error: 'llvm/TableGen/Error.h' file not found
#include "llvm/TableGen/Error.h"
         ^
1 error generated.
mkdep: compile failed
*** [.depend] Error code 1

Stop in /usr/src/lib/clang/libllvmtablegen.
*** [bootstrap-tools] Error code 1

Stop in /usr/src.
*** [_bootstrap-tools] Error code 1

Stop in /usr/src.
*** [buildworld] Error code 1

Stop in /usr/src.