interactions between clSetKernelArg and cl_ext_immutable_memory_objects need to be specified.

The OpenCL CTS already tests for this, but I think the spec also needs to be adjusted there:

CL_INVALID_ARG_VALUE
- if the argument is a buffer and arg_value refers to an image object created with cl_mem_flags of CL_MEM_IMMUTABLE_EXT, or
- if the argument is an image declared with the read_only qualifier and arg_value refers to an image object created with cl_mem_flags of CL_MEM_WRITE_ONLY, or
- if the image argument is declared with the write_only qualifier and arg_value refers to an image object created with cl_mem_flags of CL_MEM_READ_ONLY or CL_MEM_IMMUTABLE_EXT.

Anything I'm missing there (should probably have created a PR directly...)?

Start by locating the specification text for clSetKernelArg and the cl_ext_immutable_memory_objects extension, then compare the stated cases with the existing OpenCL CTS coverage. Check whether any interaction cases are missing. Done means the specification defines the relevant CL_INVALID_ARG_VALUE behavior and remains consistent with the CTS tests.

Written by the indexing model from the issue text.