Avoid accessing invalid std::vector element; this makes clang ENABLE_EXPENSIVE_CHECKS clean on x86_64-.*-darwin10.
Avoid accessing invalid std::vector element; this makes clang
ENABLE_EXPENSIVE_CHECKS clean on x86_64-.*-darwin10.


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@77831 91177308-0d34-0410-b5e6-96231b3b80d8

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