message: Little more cleanup on
  Thanks Jonas...  One more early continue and using
  a range where we had an iterator.
  NFC
diff: @@ -211,11 +211,11 @@ bool PathMappingList::FindFile(const FileSpec &orig_spec,
  bool orig_is_relative = orig_spec.IsRelative();
  - const_iterator pos, end = m_pairs.end();
  - for (pos = m_pairs.begin(); pos != end; ++pos) {
  + for (auto entry : m_pairs) {
  llvm::StringRef orig_ref(orig_path);
  - llvm::StringRef prefix_ref = pos->first.GetStringRef();
  - if (orig_ref.size() >= prefix_ref.size()) {
  + llvm::StringRef prefix_ref = entry.first.GetStringRef();
  + if (orig_ref.size() < prefix_ref.size())
  + continue;
  // We consider a relative prefix or one of just "." to
  // mean "only apply to relative paths".
  bool prefix_is_relative = false;
  @@ -233,13 +233,12 @@ bool PathMappingList::FindFile(const FileSpec &orig_spec,
  continue;
  if (orig_ref.consume_front(prefix_ref)) {
  - new_spec.SetFile(pos->second.GetCString(), FileSpec::Style::native);
  + new_spec.SetFile(entry.second.GetCString(), FileSpec::Style::native);
  new_spec.AppendPathComponent(orig_ref);
  if (FileSystem::Instance().Exists(new_spec))
  return true;
  }
  }
  - }
  new_spec.Clear();
  return false;
  