Pascal filesystem adds zero-length files incorrectly

[fadden]

Adding a zero-length file to a Pascal filesystem creates an entry where the "start" and "next" blocks are the same. It should instead create an entry that occupies one block, but has a "bytes in last block" value of zero.

The problem with zero-block files is that it creates the possibility of having multiple files with the same start block.

(Zero-length files will be deleted by Apple Pascal when the system boots, so they're of limited value.)