message: Fix ComputeGuessScore and delete dead code
  Thanks to CXuesong
diff: @@ -256,7 +256,7 @@ std::vector<Project::Entry> LoadFromDirectoryListing(ProjectConfig *config) {
  e.filename = file;
  e.args = GetCompilerArgumentForFile(file);
  if (e.args.empty())
  - e.args.push_back("%clang"); // Add a Dummy.
  + e.args.push_back("%clang");
  e.args.push_back(Intern(e.filename));
  proc.Process(e);
  result.push_back(e);
  @@ -364,7 +364,7 @@ LoadEntriesFromDirectory(ProjectConfig *project,
  // argument guessing.
  int ComputeGuessScore(std::string_view a, std::string_view b) {
  // Increase score based on common prefix and suffix. Prefixes are prioritized.
  - if (a.size() < b.size())
  + if (a.size() > b.size())
  std::swap(a, b);
  size_t i = std::mismatch(a.begin(), a.end(), b.begin()).first - a.begin();
  size_t j = std::mismatch(a.rbegin(), a.rend(), b.rbegin()).first - a.rbegin();
  @@ -407,19 +407,6 @@ void Project::Load(const std::string &root) {
  }
  }
  -void Project::SetArgsForFile(const std::vector<const char *> &args,
  - const std::string &path) {
  - std::lock_guard<std::mutex> lock(mutex_);
  - for (auto &[root, folder] : root2folder) {
  - auto it = folder.path2entry_index.find(path);
  - if (it != folder.path2entry_index.end()) {
  - // The entry already exists in the project, just set the flags.
  - folder.entries[it->second].args = args;
  - return;
  - }
  - }
  -}
  -
  Project::Entry Project::FindEntry(const std::string &path,
  bool can_be_inferred) {
  std::lock_guard<std::mutex> lock(mutex_);
  