Fix some OpenCL compilation errors.
Fix some OpenCL compilation errors.

In particular, if the CL file isn't found, then abort. Also '-g' is
not a valid OpenCL compiler option all the time...

Mokosha/GenTC,Mokosha/GenTC,Mokosha/GenTC,Mokosha/GenTC,Mokosha/GenTC,Mokosha/GenTC