clangbsd svn compilation error

i just grabbed a svn snapshot of clangbsd and did a buildworld inside it, but
i'm getting this error:

c++ -O2 -fno-strict-aliasing -pipe
-I/usr/local/src/clangbsd/usr.bin/clang/bin/tblgen/../../../../contrib/llvm/include
-I/usr/local/src/clangbsd/usr.bin/clang/bin/tblgen/../../../../contrib/llvm/tools/clang/include
-I/usr/local/src/clangbsd/usr.bin/clang/bin/tblgen/../../../../contrib/llvm/utils/TableGen
-I. -I/usr/local/src/clangbsd/usr.bin/clang/bin/tblgen/../../include
-DLLVM_ON_UNIX -DLLVM_ON_FREEBSD -D__STDC_LIMIT_MACROS
-D__STDC_CONSTANT_MACROS -DLLVM_HOSTTRIPLE=\"i386-undermydesk-freebsd8.0\"
-I/usr/obj/usr/local/src/clangbsd/tmp/legacy/usr/include -fconserve-space
-static -L/usr/obj/usr/local/src/clangbsd/tmp/legacy/usr/lib -o tblgen
AsmWriterEmitter.o CallingConvEmitter.o ClangDiagnosticsEmitter.o
CodeEmitterGen.o CodeGenDAGPatterns.o CodeGenInstruction.o CodeGenTarget.o
DAGISelEmitter.o FastISelEmitter.o InstrEnumEmitter.o InstrInfoEmitter.o
IntrinsicEmitter.o LLVMCConfigurationEmitter.o Record.o RegisterInfoEmitter.o
SubtargetEmitter.o TGLexer.o TGParser.o TGValueTypes.o TableGen.o
TableGenBackend.o
/usr/obj/usr/local/src/clangbsd/tmp/usr/local/src/clangbsd/usr.bin/clang/bin/tblgen/../../lib/libllvmsupport/libllvmsupport.a
/usr/obj/usr/local/src/clangbsd/tmp/usr/local/src/clangbsd/usr.bin/clang/bin/tblgen/../../lib/libllvmsystem/libllvmsystem.a
-lpthread -legacy
/usr/obj/usr/local/src/clangbsd/tmp/usr/local/src/clangbsd/usr.bin/clang/bin/tblgen/../../lib/libllvmsystem/libllvmsystem.a(Atomic.o)(.text+0x25):
In function `llvm::sys::AtomicIncrement(unsigned int volatile*)':
: undefined reference to `__sync_add_and_fetch_4'
/usr/obj/usr/local/src/clangbsd/tmp/usr/local/src/clangbsd/usr.bin/clang/bin/tblgen/../../lib/libllvmsystem/libllvmsystem.a(Atomic.o)(.text+0x45):
In function `llvm::sys::AtomicDecrement(unsigned int volatile*)':
: undefined reference to `__sync_sub_and_fetch_4'
/usr/obj/usr/local/src/clangbsd/tmp/usr/local/src/clangbsd/usr.bin/clang/bin/tblgen/../../lib/libllvmsystem/libllvmsystem.a(Atomic.o)(.text+0x5):
In function `llvm::sys::AtomicAdd(unsigned int volatile*, unsigned int)':
: undefined reference to `__sync_add_and_fetch_4'
/usr/obj/usr/local/src/clangbsd/tmp/usr/local/src/clangbsd/usr.bin/clang/bin/tblgen/../../lib/libllvmsystem/libllvmsystem.a(Atomic.o)(.text+0x61):
In function `llvm::sys::CompareAndSwap(unsigned int volatile*, unsigned int,
unsigned int)':
: undefined reference to `__sync_val_compare_and_swap_4'
*** Error code 1

Stop in /usr/local/src/clangbsd/usr.bin/clang/bin/tblgen.
*** Error code 1

Stop in /usr/local/src/clangbsd.
*** Error code 1

Stop in /usr/local/src/clangbsd.
*** Error code 1

Stop in /usr/local/src/clangbsd.

i followed the instructions on the wiki. i'm running r195247 (HEAD) and the
revision of the clangbsd svn snapshot i was trying to build is 195329. i have
llvm-devel-2.6.r71086 installed and running gcc version 4.2.1 20070719 (the
one that comes with world).

cheers.
alex