Enable synthesized Codable impls for tests

Author: Itai Ferber

test/stdlib/TestJSONEncoder.swift

@@ -1234,27 +1234,6 @@ fileprivate class Person : Codable, Equatable {
     self.website = website
   }
 
-  private enum CodingKeys : String, CodingKey {
-    case name
-    case email
-    case website
-  }
-
-  // FIXME: Remove when subclasses (Employee) are able to override synthesized conformance.
-  required init(from decoder: Decoder) throws {
-    let container = try decoder.container(keyedBy: CodingKeys.self)
-    name = try container.decode(String.self, forKey: .name)
-    email = try container.decode(String.self, forKey: .email)
-    website = try container.decodeIfPresent(URL.self, forKey: .website)
-  }
-
-  func encode(to encoder: Encoder) throws {
-    var container = encoder.container(keyedBy: CodingKeys.self)
-    try container.encode(name, forKey: .name)
-    try container.encode(email, forKey: .email)
-    try container.encodeIfPresent(website, forKey: .website)
-  }
-
   func isEqual(_ other: Person) -> Bool {
     return self.name == other.name &&
            self.email == other.email &&

test/stdlib/TestPlistEncoder.swift

@@ -474,27 +474,6 @@ fileprivate class Person : Codable, Equatable {
     self.website = website
   }
 
-  private enum CodingKeys : String, CodingKey {
-    case name
-    case email
-    case website
-  }
-
-  // FIXME: Remove when subclasses (Employee) are able to override synthesized conformance.
-  required init(from decoder: Decoder) throws {
-    let container = try decoder.container(keyedBy: CodingKeys.self)
-    name = try container.decode(String.self, forKey: .name)
-    email = try container.decode(String.self, forKey: .email)
-    website = try container.decodeIfPresent(URL.self, forKey: .website)
-  }
-
-  func encode(to encoder: Encoder) throws {
-    var container = encoder.container(keyedBy: CodingKeys.self)
-    try container.encode(name, forKey: .name)
-    try container.encode(email, forKey: .email)
-    try container.encodeIfPresent(website, forKey: .website)
-  }
-
   func isEqual(_ other: Person) -> Bool {
     return self.name == other.name &&
            self.email == other.email &&