Fix casts in RegionStore to not always assume that bindings are only to SubRegions.  Fixes assertion failure reported in PR 7572.
Fix casts in RegionStore to not always assume that bindings are only to SubRegions.  Fixes assertion failure
reported in PR 7572.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@107738 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang