One small thing that I have not done that Jakub and several other have asked me before is that, there are no tests in c-c++-common for _Cilk_for. The reason being that the syntax between C and C++ implementations are different. In C++, the induction variable must be defined in the initializer (e.g. it should start wth _Cilk_for (int ii = 0....)). In C, this is not allowed (e.g. it should start as _Cilk_for (ii = 0; ii < 10; ii++)).
For pragma simd what I did was put the tests in c-c++-common and pass "-std=c99" to the C tests. That should allow declaration at initialization.
Can you do this? Aldy