PATCH: Fix gij stack traces

[Tom Tromey]

Bryce> Eventually we want to have a common entry point into libgcj
Bryce> that is used by gij, jv-genmain, and both JNI and CNI
Bryce> invocation (as opposed to the current situation where we have
Bryce> separate entry points with separate argument processing, etc).

Yeah.  I imagine we'll have something like a CNI-based invocation API.
It isn't too high on the list but it is definitely a known thing to
do.  That will let us implement the JNI invocation API correctly as
well.

Tom