DebugRef.Object is public
We had used bogus interp.Array when we should have had interp.Structure. address
some of those issues. Some other probably still remain.
interp.go:
*  visitInstr() save instruction to pass off to debugger
*  save ssa2.DebugRef ifnormation
*  panic uses source Panic not interpreter panic
*  fix wrong Goroutine parameter in go() call.
*  index check channel index
*  index check array index

reflect.go:
   fill in reflect-value Structure properly