Combining SCOPE regions

[law@redhat.com]

 In message <20020620065715.GD18693@atrey.karlin.mff.cuni.cz>, Jan Hubicka 
writes:
 > the handling of SEQUENCEs opens quite interesting problem - how do we
 > want to handle instruction that "belongs" to multiple regions - like
 > when for instance combine combines instructions from two different
 > regions.  I am thinking about writing fucntion "combined_scope (scope1,
 > scope2)" that will simply choose the inner one in case they are nested
 > or return the first one in case it is non-NULL.  Is there better way to
 > do so?
I think we just have to pick one.  This is the kind of case where optimization
will make debugging harder.  

jeff