libclc: fix convert with half (#99481)

Fix following update of libclc introducing more fp16 support:
https://github.com/llvm/llvm-project/commit/7e6a73959ae97b1f9476a90290a492ba90cb950d

GitOrigin-RevId: d9cb65ff483a2f79d0d3f0239796abe829372e52
2 files changed