A name the platform declares filed an entry under that system before
its own system:, and the last declaration of a name won. fmsx's 16 KB
DISK.ROM went to nec-pc-88 for quasi88's 2 KB disk.rom and came out as
a second DISK.ROM line under "NEC - PC-8801"; dosbox's SC-55
ROM1.BIN/ROM2.BIN went to galaksija.
A declaration now files an entry only when it can be the same file: a
shared hash, or no size both admit. The same content declared under two
systems is filed under both, an entry's own system stands against a
refuted homonym, and a systemless profile's placeholder takes only names
the platform does not declare. Merging reads the same size rule, so a
24 KB ROM and an entry capped at 16 KB stay two files.