Convert internal representation to use DAG. This gives us more flexibility and enables future improvements.
Convert internal representation to use DAG. This gives us more flexibility and enables future improvements.


git-svn-id: a4a6f32337ebd29ad4763b423022f00f68d1c7b7@50724 91177308-0d34-0410-b5e6-96231b3b80d8

lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx