Hello,

This patch changes the frame creation code so that it can unwind the PC 
before doing anything else.  By unwinding the PC first, it becomes 
possible to correctly set the frame from the outset.  The old code would 
set the frame's type last (resulting in architecture code having to back 
patch it).   It also (at least in theory) makes it possible to avoid 
certain frame unwinds.

Since, right now, all architectures currently specify a deprecated init 
frame pc method, the code isn't used by any architecture.  A follow on 
will be to enable the code on at least one architecture.

I'll commit the attached in a few days,
enjoy,

Andrew