Rename the current *Occur* buffer to *Occur: original-buffer-name*.
Here `original-buffer-name' is the buffer name where Occur was originally run.
When given the prefix argument, or called non-interactively, the renaming
will not clobber the existing buffer(s) of that name, but use
`generate-new-buffer-name' instead. You can add this to `occur-hook'
if you always want a separate *Occur* buffer for each buffer where you invoke `occur'.