Fix the variable view in the "gui" curses mode so that variables whose...

Fix the variable view in the "gui" curses mode so that variables whose children change will update correctly. Previously the variable view would update the children once and not change. If you were stepping through code where the dynamic type of a variable would change the value and its children, or a synthetic type (like say for a std::vector<int>), the variable view wouldn't update. Now it caches the children and uses the process stop ID to tell when the children need to be updated.

llvm-svn: 290688