Cause: vertex output initialization wrote ClipDistance[0..7] whenever any clip distance was used, while vtg-as-compute output reservations can be sparse.
Effect: the mismatch could leave unreserved ClipDistance stores in the IR path and trigger downstream translation failures.
Fix: initialize only the ClipDistance components flagged in ClipDistancesWritten by iterating the bitmask with BitOperations.TrailingZeroCount.
jebbs
438bf95f3f