fix: start lines name alternatives, not extras

A file most of whose readers take beside another one is no start file
(NAOMI opened on hod2bios.zip), and names that answer one slot for
different emulators read as alternatives with their readers, each by
the name of its card.

tests/test_site_r2_systems.py

@@ -114,7 +114,11 @@ class TheConsoleBiosComesFirst(unittest.TestCase):
 
     def test_a_long_list_names_the_first_and_counts_the_rest(self):
         files = [_file(f"rom{i}.bin", "abcdefgh"[i]) for i in range(8)]
+        # One emulator requires all eight: files each required by another
+        # emulator are other names for one slot (round 5, 6.2).
         consumers = _consumers({f["sha1"]: [{"required": True}] for f in files})
+        consumers.emulator_files = {"emu": [{"required": True}] * len(files)}
+        consumers.emulator_entries = {f["sha1"]: {"emu": i} for i, f in enumerate(files)}
         self.assertEqual(gs._start_with(files, consumers)[0],
                          "**Start with**: `rom0.bin`, `rom1.bin`, `rom2.bin` and 5 more files. "
                          "They come first below.")