Following rmathew's advice, I looked for a cl.exe (the Win32 compiler) flag equivalent to gcj's -fno-omit-frame-pointer. Which actually exists.

I then had a fun little time disassembling the resulting library to ensure this flag had the desired effect (I used REC for this purpose, a nice but sadly not open-sourced software).

Well, it did, but this did not solve my crashing issues. At this point, it seems like I really should study and trace gcj's stack unwinding code...