Don't hashmap functions smaller than 16 bytes

Otherwise, small stub funcs "replicate" annoyingly.

Use case:

```
z_un_A:
j zz_sceRead
nop

z_un_B:
j zz_sceReadAsync
nop
```

If I rename `z_un_A` to `sceRead`, the hashmap will "helpfully" replace all functions that match that template (including `z_un_B`) with `sceRead` (they have identical hashes, after all.)

Need to omit functions that are small.

-[Unknown]