Add a reverse iterator to DeclStmt, and use it when building a CFG.

The CFG creates dummy DeclStmts with one Decl per statement, and it has
to do so from last to first in order to build the graph correctly.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160560 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed