This is how I would interpret the suggestion in the linked question.
Put everything but the bibliography in one (or more) file(s), and the bibliography material in a separate file, and pull all of them in with \includes. Process the whole job as many times as necessary, until all cross-references are resolved.
When there are no more errors (or warnings), use \includeonly to process the main text file(s) separately. All the existing .aux files will be read in, so the result should be the same as the full run, except that the bibliography won't be at the end. Rename that .pdf file so it won't be lost.
Now, change the \includeonly to pull in only the bibliography. Again, all existing .aux files will be read in, although they're probably not needed. The resulting .pdf file will contain only the bibliography. Rename that .pdf file to a name different from the main text .pdf.
Now you have two separate .pdf files, each with different content, as you have requested.