moving the clang-omp merge along

Hi Chandler,

3) we need a good switch in Clang to use iomp (I know you or someone on the
patch thread worked on this, did it land? if so, done!)

There is option -fopenmp=libiomp5 which makes clang to generate OpenMP code for libiomp5. Currently the code is generated only for '#pragma omp parallel' (just some initial codegen, you can check test in clang/test/OpenMP/parallel_codegen.cpp). I'm working on CodeGen for '#pragma omp threadprivate'. It will be ready soon.

Best regards,
Alexey Bataev