Native bindings to the qcom_ext_host_ptr_iocoherent extension.

This extension extends the functionality provided by cl_qcom_ext_host_ptr by adding a new host cache policy. It allows applications to specify a new value, MEM_HOST_IOCOHERENT_QCOM, for cl_mem_ext_host_ptr::host_cache_policy. When the application selects this value for host cache policy, the imported allocation is mapped as io-coherent for the GPU. This in turn avoids the need for the OpenCL driver to explicitly issue CPU cache operation calls. Although GPU performance can be slower in some cases for io-coherent allocations, the overall performance can improve due to the elimination of explicit CPU cache operations.

Requires CL11 and qcom_ext_host_ptr.