message: [vcpkg] x-add-version improve speed by calling get_builtin_baseline only once
  Currently get_builtin_baseline is called for every port and 95% of the runtime
  is spend inside of get_builtin_baseline when using --all
diff: @@ -116,20 +116,10 @@ namespace
  const std::string& port_name,
  const VersionT& version,
  const fs::path& baseline_path,
  + std::map<std::string, vcpkg::VersionT, std::less<>>& baseline_map,
  bool print_success)
  {
  - bool is_new_file = false;
  auto& fs = paths.get_filesystem();
  - auto baseline_map = [&]() -> std::map<std::string, vcpkg::VersionT, std::less<>> {
  - if (!fs.exists(VCPKG_LINE_INFO, baseline_path))
  - {
  - is_new_file = true;
  - std::map<std::string, vcpkg::VersionT, std::less<>> ret;
  - return ret;
  - }
  - auto maybe_baseline_map = vcpkg::get_builtin_baseline(paths);
  - return maybe_baseline_map.value_or_exit(VCPKG_LINE_INFO);
  - }();
  auto it = baseline_map.find(port_name);
  if (it != baseline_map.end())
  @@ -157,10 +147,9 @@ namespace
  if (print_success)
  {
  System::printf(System::Color::success,
  - "Added version `%s` to `%s`%s.\n",
  + "Added version `%s` to `%s`.\n",
  version.to_string(),
  - fs::u8string(baseline_path),
  - is_new_file ? " (new file)" : "");
  + fs::u8string(baseline_path));
  }
  return;
  }
  @@ -335,6 +324,16 @@ namespace vcpkg::Commands::AddVersion
  }
  }
  + auto baseline_map = [&]() -> std::map<std::string, vcpkg::VersionT, std::less<>> {
  + if (!fs.exists(VCPKG_LINE_INFO, baseline_path))
  + {
  + std::map<std::string, vcpkg::VersionT, std::less<>> ret;
  + return ret;
  + }
  + auto maybe_baseline_map = vcpkg::get_builtin_baseline(paths);
  + return maybe_baseline_map.value_or_exit(VCPKG_LINE_INFO);
  + }();
  +
  // Get tree-ish from local repository state.
  auto maybe_git_tree_map = paths.git_get_local_port_treeish_map();
  auto git_tree_map = maybe_git_tree_map.value_or_exit(VCPKG_LINE_INFO);
  @@ -370,7 +369,7 @@ namespace vcpkg::Commands::AddVersion
  fs::u8path(Strings::concat(port_name, ".json"));
  update_version_db_file(
  paths, port_name, schemed_version, git_tree, port_versions_path, overwrite_version, verbose, add_all);
  - update_baseline_version(paths, port_name, schemed_version.versiont, baseline_path, verbose);
  + update_baseline_version(paths, port_name, schemed_version.versiont, baseline_path, baseline_map, verbose);
  }
  Checks::exit_success(VCPKG_LINE_INFO);
  }
  