gdb: make value::allocate_register_lazy store id of next non-inline frame

gdb: make value::allocate_register_lazy store id of next non-inline frame

Some spots loop on the frame chain to find the first next non-inline
frame, and pass that as the "next frame" to
value::allocate_register_lazy / value::allocate_register.  This is
necessary if the value is used in the process of computing the id of
"this frame".  If the frame next to "this frame" is inlined into "this
frame", then you that next frame won't have a computed id yet.  You have
to go past that to find the next non-inline frame, which will have a
computed id.

In other cases, it's fine to store the id of an inline frame as the
"next frame id" in a register struct value.  When trying to unwind a
register from it, it will just call inline_frame_prev_register, which
will forward the request to the next next frame, until we hit the next
physical frame.

I think it would make things simpler to just never store the id of an
inline frame as the next frame id of register struct values, and go with
the first next non-inline frame directly.  This way, we don't have to
wonder which code paths have to skip inline frames when creating
register values and which don't.

So, change value::allocate_register_lazy to do that work, and remove the
loops for the callers that did it.

Change-Id: Ic88115dac49dc14e3053c95f92050062b24b7310