Harden Clang's cursor visitation logic against NULL declaration, statement, and expression pointers. While these shouldn't happen, it's better to be safe in libclang.
Harden Clang's cursor visitation logic against NULL declaration,
statement, and expression pointers. While these shouldn't happen, it's
better to be safe in libclang.


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@129539 91177308-0d34-0410-b5e6-96231b3b80d8

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