omp_is_initial_device commit small issue

With the commit "OpenMP 4.0 standard function omp_is_initial_device()
implemented." we now have conflicting symbols compared to our own
device offloading support

This will probably be true for the following:
omp_set_default_device
omp_get_default_device
omp_get_num_devices
omp_is_initial_device

Are you getting error messages from the linker?

When I compile both the offload and runtime libraries then run a little offloading program with all four interface functions, I do not get conflicting symbols at link or load time. The omp_*_default_device(), omp_get_num_devices() functions are only defined for MIC and Mac inside libiomp5. For Linux, they are only defined in liboffload. And omp_is_initial_device() is only defined in libiomp5 for all platforms. It is a little confusing...

There is an issue with Windows buildsL: omp_[s|g]et_default_device() and omp_get_num_devices() aren't defined anywhere (liboffload.so.5 is only buildable on linux).

-- Johnny