Rework enums to use the same name mapping as message fields. (apple#320)

* Rename FieldNameMap to just _NameMap and use it with enums.
Along with some other various cleanup.
* Regenerate tests.
* Update reference protos.

Author: allevato

Reference/conformance/conformance.pb.swift

@@ -68,13 +68,19 @@ fileprivate struct _GeneratedWithProtocGenSwiftVersion: SwiftProtobuf.ProtobufAP
 //    - running as a sub-process may be more tricky in unusual environments like
 //      iOS apps, where fork/stdin/stdout are not available.
 
-enum Conformance_WireFormat: SwiftProtobuf.Enum {
+enum Conformance_WireFormat: SwiftProtobuf.Enum, SwiftProtobuf._ProtoNameProviding {
   typealias RawValue = Int
   case unspecified // = 0
   case protobuf // = 1
   case json // = 2
   case UNRECOGNIZED(Int)
 
+  static let _protobuf_nameMap: SwiftProtobuf._NameMap = [
+    0: .same(proto: "UNSPECIFIED"),
+    1: .same(proto: "PROTOBUF"),
+    2: .same(proto: "JSON"),
+  ]
+
   init() {
     self = .unspecified
   }
@@ -88,43 +94,12 @@ enum Conformance_WireFormat: SwiftProtobuf.Enum {
     }
   }
 
-  init?(jsonName: String) {
-    switch jsonName {
-    case "UNSPECIFIED": self = .unspecified
-    case "PROTOBUF": self = .protobuf
-    case "JSON": self = .json
-    default: return nil
-    }
-  }
-
-  init?(protoName: String) {
-    switch protoName {
-    case "UNSPECIFIED": self = .unspecified
-    case "PROTOBUF": self = .protobuf
-    case "JSON": self = .json
-    default: return nil
-    }
-  }
-
   var rawValue: Int {
-    get {
-      switch self {
-      case .unspecified: return 0
-      case .protobuf: return 1
-      case .json: return 2
-      case .UNRECOGNIZED(let i): return i
-      }
-    }
-  }
-
-  var _protobuf_jsonName: String? {
-    get {
-      switch self {
-      case .unspecified: return "UNSPECIFIED"
-      case .protobuf: return "PROTOBUF"
-      case .json: return "JSON"
-      case .UNRECOGNIZED: return nil
-      }
+    switch self {
+    case .unspecified: return 0
+    case .protobuf: return 1
+    case .json: return 2
+    case .UNRECOGNIZED(let i): return i
     }
   }
 
@@ -138,7 +113,7 @@ enum Conformance_WireFormat: SwiftProtobuf.Enum {
 struct Conformance_ConformanceRequest: SwiftProtobuf.Proto3Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
   static let protoMessageName: String = "ConformanceRequest"
   static let protoPackageName: String = "conformance"
-  static let _protobuf_fieldNames: FieldNameMap = [
+  static let _protobuf_nameMap: SwiftProtobuf._NameMap = [
     1: .unique(proto: "protobuf_payload", json: "protobufPayload"),
     2: .unique(proto: "json_payload", json: "jsonPayload"),
     3: .unique(proto: "requested_output_format", json: "requestedOutputFormat"),
@@ -255,7 +230,7 @@ struct Conformance_ConformanceRequest: SwiftProtobuf.Proto3Message, SwiftProtobu
 struct Conformance_ConformanceResponse: SwiftProtobuf.Proto3Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
   static let protoMessageName: String = "ConformanceResponse"
   static let protoPackageName: String = "conformance"
-  static let _protobuf_fieldNames: FieldNameMap = [
+  static let _protobuf_nameMap: SwiftProtobuf._NameMap = [
     1: .unique(proto: "parse_error", json: "parseError"),
     6: .unique(proto: "serialize_error", json: "serializeError"),
     2: .unique(proto: "runtime_error", json: "runtimeError"),

Reference/google/protobuf/any.pb.swift

@@ -120,7 +120,7 @@ fileprivate struct _GeneratedWithProtocGenSwiftVersion: SwiftProtobuf.ProtobufAP
 struct Google_Protobuf_Any: SwiftProtobuf.Proto3Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
   static let protoMessageName: String = "Any"
   static let protoPackageName: String = "google.protobuf"
-  static let _protobuf_fieldNames: FieldNameMap = [
+  static let _protobuf_nameMap: SwiftProtobuf._NameMap = [
     1: .unique(proto: "type_url", json: "typeUrl"),
     2: .same(proto: "value"),
   ]

Reference/google/protobuf/any_test.pb.swift

@@ -52,7 +52,7 @@ fileprivate struct _GeneratedWithProtocGenSwiftVersion: SwiftProtobuf.ProtobufAP
 struct ProtobufUnittest_TestAny: SwiftProtobuf.Proto3Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
   static let protoMessageName: String = "TestAny"
   static let protoPackageName: String = "protobuf_unittest"
-  static let _protobuf_fieldNames: FieldNameMap = [
+  static let _protobuf_nameMap: SwiftProtobuf._NameMap = [
     1: .unique(proto: "int32_value", json: "int32Value"),
     2: .unique(proto: "any_value", json: "anyValue"),
     3: .unique(proto: "repeated_any_value", json: "repeatedAnyValue"),

Reference/google/protobuf/api.pb.swift

@@ -52,7 +52,7 @@ fileprivate struct _GeneratedWithProtocGenSwiftVersion: SwiftProtobuf.ProtobufAP
 struct Google_Protobuf_Api: SwiftProtobuf.Proto3Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
   static let protoMessageName: String = "Api"
   static let protoPackageName: String = "google.protobuf"
-  static let _protobuf_fieldNames: FieldNameMap = [
+  static let _protobuf_nameMap: SwiftProtobuf._NameMap = [
     1: .same(proto: "name"),
     2: .same(proto: "methods"),
     3: .same(proto: "options"),
@@ -233,7 +233,7 @@ struct Google_Protobuf_Api: SwiftProtobuf.Proto3Message, SwiftProtobuf._MessageI
 struct Google_Protobuf_Method: SwiftProtobuf.Proto3Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
   static let protoMessageName: String = "Method"
   static let protoPackageName: String = "google.protobuf"
-  static let _protobuf_fieldNames: FieldNameMap = [
+  static let _protobuf_nameMap: SwiftProtobuf._NameMap = [
     1: .same(proto: "name"),
     2: .unique(proto: "request_type_url", json: "requestTypeUrl"),
     3: .unique(proto: "request_streaming", json: "requestStreaming"),
@@ -401,7 +401,7 @@ struct Google_Protobuf_Method: SwiftProtobuf.Proto3Message, SwiftProtobuf._Messa
 struct Google_Protobuf_Mixin: SwiftProtobuf.Proto3Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
   static let protoMessageName: String = "Mixin"
   static let protoPackageName: String = "google.protobuf"
-  static let _protobuf_fieldNames: FieldNameMap = [
+  static let _protobuf_nameMap: SwiftProtobuf._NameMap = [
     1: .same(proto: "name"),
     2: .same(proto: "root"),
   ]

Reference/google/protobuf/compiler/plugin.pb.swift

@@ -69,7 +69,7 @@ fileprivate struct _GeneratedWithProtocGenSwiftVersion: SwiftProtobuf.ProtobufAP
 struct Google_Protobuf_Compiler_Version: SwiftProtobuf.Proto2Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
   static let protoMessageName: String = "Version"
   static let protoPackageName: String = "google.protobuf.compiler"
-  static let _protobuf_fieldNames: FieldNameMap = [
+  static let _protobuf_nameMap: SwiftProtobuf._NameMap = [
     1: .same(proto: "major"),
     2: .same(proto: "minor"),
     3: .same(proto: "patch"),
@@ -176,7 +176,7 @@ struct Google_Protobuf_Compiler_Version: SwiftProtobuf.Proto2Message, SwiftProto
 struct Google_Protobuf_Compiler_CodeGeneratorRequest: SwiftProtobuf.Proto2Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
   static let protoMessageName: String = "CodeGeneratorRequest"
   static let protoPackageName: String = "google.protobuf.compiler"
-  static let _protobuf_fieldNames: FieldNameMap = [
+  static let _protobuf_nameMap: SwiftProtobuf._NameMap = [
     1: .unique(proto: "file_to_generate", json: "fileToGenerate"),
     2: .same(proto: "parameter"),
     15: .unique(proto: "proto_file", json: "protoFile"),
@@ -323,7 +323,7 @@ struct Google_Protobuf_Compiler_CodeGeneratorRequest: SwiftProtobuf.Proto2Messag
 struct Google_Protobuf_Compiler_CodeGeneratorResponse: SwiftProtobuf.Proto2Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
   static let protoMessageName: String = "CodeGeneratorResponse"
   static let protoPackageName: String = "google.protobuf.compiler"
-  static let _protobuf_fieldNames: FieldNameMap = [
+  static let _protobuf_nameMap: SwiftProtobuf._NameMap = [
     1: .same(proto: "error"),
     15: .same(proto: "file"),
   ]
@@ -356,7 +356,7 @@ struct Google_Protobuf_Compiler_CodeGeneratorResponse: SwiftProtobuf.Proto2Messa
   struct File: SwiftProtobuf.Proto2Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
     static let protoMessageName: String = "File"
     static let protoPackageName: String = "google.protobuf.compiler"
-    static let _protobuf_fieldNames: FieldNameMap = [
+    static let _protobuf_nameMap: SwiftProtobuf._NameMap = [
       1: .same(proto: "name"),
       2: .unique(proto: "insertion_point", json: "insertionPoint"),
       15: .same(proto: "content"),