message: Add extra checks on the return Visual Studio instances
diff: @@ -330,10 +330,19 @@ namespace vcpkg
  VCPKG_LINE_INFO, ec_data.exit_code == 0, "Could not run script to detect Visual Studio instances");
  const std::vector<std::string> instances_as_strings = Strings::split(ec_data.output, "\n");
  + Checks::check_exit(
  + VCPKG_LINE_INFO, !instances_as_strings.empty(), "Could not detect any Visual Studio instances");
  +
  std::vector<VisualStudioInstance> output;
  for (const std::string& instance_as_string : instances_as_strings)
  {
  const std::vector<std::string> split = Strings::split(instance_as_string, "::");
  + Checks::check_exit(VCPKG_LINE_INFO,
  + split.size() == 4,
  + "Invalid Visual Studio instance format.\n"
  + "Expected: PreferenceWeight::ReleaseType::Version::PathToVisualStudio\n"
  + "Actual : %s",
  + instance_as_string);
  output.push_back({split.at(3), split.at(2), split.at(1), split.at(0)});
  }
  