.mdebug parser failing on some IDO 5.3 -KPIC code

[Francessco121]

With the latest release, I'm seeing the warning: Failed to parse MIPS mdebug line info: range exceeds .mdebug size for some DLLs in the Dinosaur Planet decomp, which are all compiled with -KPIC (assuming that's relevant, might not be. haven't seen this in our non-relocatable code).

Here's an object file (compiled with IDO 5.3 -KPIC -O2 -g3 -mips2) that reproduces this on v3.3.1. snowhorn.zip

I tried to debug this myself but I didn't get very far. It appears to be blowing up here: https://github.com/encounter/objdiff/blob/v3.3.1/objdiff-core/src/obj/mdebug.rs#L43-L51

Fwiw, running objdump on the file seems to show line numbers just fine so I don't think the file is corrupt? (either that or objdump just doesn't care).