Unknown FDE encoding - known issue? Resolved?

[Steve Fink]

I apologize for the lack of detail, but this is a problem I ran into a
while back while compiling Mozilla Firefox as a ppc executable (to be
included in a universal binary). Mozilla is dropping support for ppc,
but before I just abandon the bug I thought I should check to see if
this is a known issue.

The exact error message was "unsupported encoding in FDE". See
https://bugzilla.mozilla.org/show_bug.cgi?id=582690

I resolved it with the following patch, which I created but don't
begin to understand:
https://bug582690.bugzilla.mozilla.org/attachment.cgi?id=460945 (it
was based off some random web search result that I didn't archive.)

It switches the FDE (Flying Donkey Earmuff?) encoding from 0x90 to
0x10. That fixes the compile. Whether it actually now does what it's
supposed to, I've no clue.

If it's been resolved in a newer libffi, I might try importing that
into Mozilla.

Thanks,
Steve