Add "cl_apple_gl_sharing" for OS X
Add "cl_apple_gl_sharing" for OS X

See https://www.khronos.org/registry/cl/sdk/1.1/docs/man/xhtml/gl_sharing.html
Poulpy21/vexcl,kapadia/vexcl,kapadia/vexcl,ddemidov/vexcl,Poulpy21/vexcl,ddemidov/vexcl,Poulpy21/vexcl