As suggested in RFC: https://lists.llvm.org/pipermail/cfe-dev/2021-June/068318.html set default version OpenCL C to 1.2. This means that the absence of any standard flag will be equivalent to passing -cl-std=CL1.2.
Note that this patch also fixes incorrect version check for the pointer to pointer kernel arguments.
Would it be worth having an invocation without any -cl-std= and verifying that it produces the same version metadata as CL1.2?