Regenerate buffer-identification after `clone-indirect-buffer`

When cloning a buffer with `clone-indirect-buffer`, the clone's `buffer-identification` is not updated, leading to it having the same identification as its parent. It makes it verry difficult to distinguish between both clones.

The following patch should correct this, by simply advising `clone-indirect-buffer` in the same way as `rename-buffer` or `set-visited-filename`.