Support for machines without AMD drivers.

[fabulouspanda]

AMD drivers are not available for Mac, and reliance on those drivers prevents running on other OpenCL devices (such as Intel graphics) so I was wondering whether you'd mind supporting machines that lack the drivers?

I can compile for Mac after making a few changes:

use

#if defined(APPLE) || defined(__MACOSX)
#include <OpenCL/cl.h>
#else
#include <CL/cl.h>
#endif

when including cl

remove these two lines of code from sgminer.c which I note have caused issues for some other users too:

FILE _iob[] = { *stdin, *stdout, *stderr };
extern "C" FILE * __cdecl __iob_func(void) { return _iob; }

in util.c replace #ifdef CLOCK_MONOTONIC /* Essentially just linux */ with #ifdef CLOCK_MONOTONIC && !defined(__APPLE__) /* Essentially just linux */

in x17.c replace inline void x17hash(void *state, const void *input) with static inline void x17hash(void *state, const void *input)

But running results in the error warning: unknown OpenCL extension 'cl_amd_media_ops2' - ignoring failed to init GPU

due to missing the drivers.