The cl_offline_compiler program used for offline compilation must
implement the following interface.

   usage: cl_offline_compiler --source FILE --output FILE
                              --cl-device-info FILE --mode MODE
                              -- [BUILD_OPTIONS [BUILD_OPTIONS ...]]

   positional arguments:
     BUILD_OPTIONS          additional options to pass to the compiler

   optional arguments:
     --source FILE          OpenCL C source file to compile
     --output FILE          SPIR-V or binary file to create
     --cl-device-info FILE  OpenCL device info file
     --mode                 compilation mode (spir-v or binary)

The --cl-device-info file is a list of KEY=VALUE pairs containing device
information relevant to the mode of offline compilation in question.
It is of the following form:

   # OpenCL device info affecting <SPIR-V|binary> offline compilation:
   CL_DEVICE_ADDRESS_BITS=<32|64>
   CL_DEVICE_EXTENSIONS="<space separated list of CL extensions>"
   CL_DEVICE_IL_VERSION="<space separated list of IL versions>"
   CL_DEVICE_VERSION="OpenCL <version> <vendor info>"
