The OpenCL API headers in this package are unified headers and are designed to work
with all released OpenCL versions. This differs from previous OpenCL API headers,
where version-specific API headers either existed in separate branches, or
in separate folders in a branch.
By default, the OpenCL API headers in this repository are for the latest OpenCL
version supported. To use these API headers to target a different OpenCL version,
an application may #define the preprocessor value CL_TARGET_OPENCL_VERSION before
including the OpenCL API headers. The CL_TARGET_OPENCL_VERSION is a three digit
decimal value representing the OpenCL API version.