Himm...
Here is a problem.
I updated LLVM-trunk and installed.
Than run this commands:

git clone http://llvm.org/git/libclc.git
cd libclc
./configure.py
make

but  got this error:

LLVM-CC nvptx--nvidiacl/lib/workitem/get_global_size.cl.bc
LLVM-LINK nvptx--nvidiacl/lib/builtins.link.bc
OPT nvptx--nvidiacl/lib/builtins.opt.bc
CXX utils/prepare-builtins.o
./utils/prepare-builtins.cpp:3:27: fatal error: llvm/Function.h: No such file
or directory
compilation terminated.

I think llvm changed llvm/Function.h files location to llvm/IR/Function.h...