[libunwind] remote unwinding and dynamically-generated code

[Todd L Miller]

        Two questions.  The first is most likely wishful thinking: will
_U_dyn_register() affect the results of a remote unwinding?

        The second question is related: does the documentation specify
anything about how dynamic unwind information for a remote process is
supposed to be registered, and if not, could it?

        I believe I've discussed adding an explicit interface for remote
registration with DMT before, and came to the conclusion that it would be
more trouble than it would be worth to do it Right.  The concern prompting
the question above stems from the fact that my tool now works with an
unmodified (0.98.2 or 0.98.3) libunwind, and I can say "or higher" with a
reasonable amount of confidence, given those discussions.  My boss,
however, would like to see something in the docs or API about this symbol,
mostly as a concrete sign that it's not intended to change (despite, for
the most part, being an internal implementation detail).

        Thanks.

- Todd L Miller