In preparation for fixing PR 6884, rework CFGElement to have getAs<> return pointers instead of fresh CFGElements.

- Also, consoldiate getDtorKind() and getKind() into one "kind".
- Add empty getDestructorDecl() method to CFGImplicitDtor.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@126738 91177308-0d34-0410-b5e6-96231b3b80d8
10 files changed