exclusive_ram_id option can trigger AssertionError

[marijnvdwerf]

Repro: https://github.com/marijnvdwerf/papermario-split/tree/906de94b6935f9f29fc678f9e996730d659d2be2

Was resolvable by defining all symbols in symbol_addrs.txt. While creating this repro, I discovered that it was also resolved by making sure that both segments had exclusive_ram_id set.

Output:

splat 0.13.4 (powered by spimdisasm 1.11.1)
Loading symbols (symbol_addrs): 100%|█████████████████████████████████████████████████████| 5/5 [00:00<00:00, 34435.99it/s]
Warning: the vram range ([0x80246AB0, 0x80251740]) of the non-global segment at rom address 0x16F4D0 overlaps with the global vram range ([0x80025C00, 0x80272490])
Scanning main:   0%|                                                                                 | 0/8 [00:00<?, ?it/s]Data segment 4B8B0, symbol at vram 80094138 is a jumptable, indicating the start of the rodata section _may_ be near here.
Please note the real start of the rodata section may be way before this point.
      - [0x6F538, rodata]
Scanning 17A160: 100%|███████████████████████████████████████████████████████████████████████| 8/8 [00:01<00:00,  6.09it/s]
Splitting filemenu:  75%|███████████████████████████████████████████████████                 | 6/8 [00:00<00:00,  7.45it/s]
Traceback (most recent call last):
  File "/Users/marijn/Projects/pmpal/tools/splat/split.py", line 562, in <module>
    main(args.config, args.modes, args.verbose, args.use_cache, args.skip_version_check)
  File "/Users/marijn/Projects/pmpal/tools/splat/split.py", line 429, in main
    segment.split(segment_bytes)
  File "/Users/marijn/Projects/pmpal/tools/splat/segtypes/common/group.py", line 112, in split
    sub.split(rom_bytes)
  File "/Users/marijn/Projects/pmpal/tools/splat/segtypes/common/c.py", line 207, in split
    assert func_sym is not None
AssertionError