Fix bug in LineState comparison function.
Fix bug in LineState comparison function.

The key bug was

  if (Other.StartOfLineLevel < StartOfLineLevel) ..

instead of

  if (Other.StartOfLineLevel != StartOfLineLevel) ..

Also cleaned up the function to be more consistent in the comparisons.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@175500 91177308-0d34-0410-b5e6-96231b3b80d8

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