__setBlockFinalizerInfo

fnvoid __setBlockFinalizerInfo(ref BlkInfo info, const TypeInfo ti) pure nothrow

The block finalizer info is set separately from the array length, as that is only needed on the initial setup of the block. No shared is needed, since this should only happen when the block is new. If the STRUCTFINAL bit is not set, no finalizer is stored (but if needed the slot is zeroed)