targets/opencl: hide all the exported llvm/clang mayhem... hopefully
Both llvm and clang polute the exported symbol table, as soon as we try to link with either one. Other than those two everything else looks good (clean). Cc: Tom Stellard <thomas.stellard@amd.com> Signed-off-by:Emil Velikov <emil.l.velikov@gmail.com> Reviewed-by:
Francisco Jerez <currojerez@riseup.net>