Add kinds for serialization.

pkg/compiler/lib/src/resolution/operators.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart2js.operators;
 
 import '../elements/elements.dart';
 import '../universe/call_structure.dart' show CallStructure;
 import '../universe/selector.dart' show Selector, SelectorKind;
 
@@ skipping 409 matching lines @@
       case '&=':
         return AND;
       case '^=':
         return XOR;
       case '|=':
         return OR;
       default:
         return null;
     }
   }
+
+  static AssignmentOperator fromKind(AssignmentOperatorKind kind) {
+    switch (kind) {
+      case AssignmentOperatorKind.ASSIGN: return ASSIGN;
+      case AssignmentOperatorKind.IF_NULL: return IF_NULL;
+      case AssignmentOperatorKind.ADD: return ADD;
+      case AssignmentOperatorKind.SUB: return SUB;
+      case AssignmentOperatorKind.MUL: return MUL;
+      case AssignmentOperatorKind.DIV: return DIV;
+      case AssignmentOperatorKind.IDIV: return IDIV;
+      case AssignmentOperatorKind.MOD: return MOD;
+      case AssignmentOperatorKind.SHL: return SHL;
+      case AssignmentOperatorKind.SHR: return SHR;
+      case AssignmentOperatorKind.AND: return AND;
+      case AssignmentOperatorKind.OR: return OR;
+      case AssignmentOperatorKind.XOR: return XOR;
+    }
+  }
 }
 
 enum IncDecOperatorKind { INC, DEC }
 
 class IncDecOperator {
   final IncDecOperatorKind kind;
   final String name;
   final BinaryOperator binaryOperator;
 
   const IncDecOperator._(this.kind, this.name, this.binaryOperator);
@@ skipping 13 matching lines @@
   static IncDecOperator parse(String value) {
     switch (value) {
       case '++':
         return INC;
       case '--':
         return DEC;
       default:
         return null;
     }
   }
+
+  static IncDecOperator fromKind(IncDecOperatorKind kind) {
+    switch (kind) {
+      case IncDecOperatorKind.INC: return INC;
+      case IncDecOperatorKind.DEC: return DEC;
+    }
+  }
 }