Some additional comments:
1) You need to use -fopenmp=libomp to enable OpenMP in clang. -fopenmp just links libgomp but ignores all the pragmas. Weird, I know — and will be changed in the trunk soon.
2) 3.7 is the first version that supports OpenMP. 3.6 doesn’t.
3) clang is only able to work with libomp. Don’t put libgomp (headers or the library) in the way of libomp! clang uses Intel API, not supported by libgomp. -fopenmp=libomp should link correct library.