Fix analyzer regression reported in PR 4164:

- Update the old StoreManager::CastRegion to strip off 'ElementRegions' when
  casting to void* (Zhongxing: please validate)
- Pass-by-reference argument invalidation logic in CFRefCount.cpp:
  - Strip ElementRegions when the ElementRegion is just a 'raw data' view
    on top of the underlying typed region.

llvm-svn: 71094