Which manufacturer made a locomotive with a type of 4-6-4t?
CREATE TABLE "west_donegal_railway" (
  "class" text,
  "type" text,
  "fleet_numbers" text,
  "quantity_made" real,
  "manufacturer" text,
  "date_made" real,
  "date_withdrawn" text
);
SELECT "manufacturer" FROM "west_donegal_railway" WHERE "type"='4-6-4t';