[kernel] Debugging of switch statement

pkg/kernel/lib/ast.dart

 // Copyright (c) 2016, 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.
 
 /// -----------------------------------------------------------------------
 ///                           ERROR HANDLING
 /// -----------------------------------------------------------------------
 ///
 /// As a rule of thumb, errors that can be detected statically are handled by
 /// the frontend, typically by translating the erroneous code into a 'throw' or
@@ skipping 3062 matching lines @@
     }
     transformList(cases, v, this);
   }
 }
 
 /// A group of `case` clauses and/or a `default` clause.
 ///
 /// This is a potential target of [ContinueSwitchStatement].
 class SwitchCase extends TreeNode {
   final List<Expression> expressions;
+  final List<int> expressionOffsets;
   Statement body;
   bool isDefault;
 
-  SwitchCase(this.expressions, this.body, {this.isDefault: false}) {
+  SwitchCase(this.expressions, this.expressionOffsets, this.body,
+      {this.isDefault: false}) {
     setParents(expressions, this);
     body?.parent = this;
   }
 
   SwitchCase.defaultCase(this.body)
       : isDefault = true,
-        expressions = <Expression>[] {
+        expressions = <Expression>[],
+        expressionOffsets = <int>[] {
     body?.parent = this;
   }
 
   SwitchCase.empty()
       : expressions = <Expression>[],
+        expressionOffsets = <int>[],
         body = null,
         isDefault = false;
 
   accept(TreeVisitor v) => v.visitSwitchCase(this);
 
   visitChildren(Visitor v) {
     visitList(expressions, v);
     body?.accept(v);
   }
 
@@ skipping 987 matching lines @@
 /// library has not been assigned a canonical name yet.
 ///
 /// Returns `null` if the library is `null`.
 CanonicalName getCanonicalNameOfLibrary(Library library) {
   if (library == null) return null;
   if (library.canonicalName == null) {
     throw '$library has no canonical name';
   }
   return library.canonicalName;
 }