states: fix handling switches inside conditions (fake_cur_stree)

states: fix handling switches inside conditions (fake_cur_stree)

This is broken from when I re-worked how the fake_cur_stree worked.  Before
that we used to randomly merge the fake_cur_stree with the cur_stree.  It
had really complicated side effects but one side effect was that this stuff
used to work.

In the current code what was happening was that when we did a break we
would discard everything from the fake_cur_stree.

Now we create a new fake stream to store these states.  We can't merge them
in with the cur_stree because we're supposed to be able to discard all
fake states.  We also can't just mix the cur_stree in with the fake
stree.  The design of the fake stree is that we have to keep it separate.
It's a little bit more complicated in some way, but more precise and
transparent in other ways...

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>