[kernel] Debugging of switch statement

pkg/kernel/lib/clone.dart

Index: pkg/kernel/lib/clone.dart
diff --git a/pkg/kernel/lib/clone.dart b/pkg/kernel/lib/clone.dart
index ce207f7d642916448b4e4fc07ee6239176781f23..7bd4f6d0ea10abba4ecc2ad1f47cdfc2d64b4ecc 100644
--- a/pkg/kernel/lib/clone.dart
+++ b/pkg/kernel/lib/clone.dart
@@ -282,8 +282,10 @@ class CloneVisitor extends TreeVisitor {
 
   visitSwitchStatement(SwitchStatement node) {
     for (SwitchCase switchCase in node.cases) {
-      switchCases[switchCase] =
-          new SwitchCase(switchCase.expressions.map(clone).toList(), null);
+      switchCases[switchCase] = new SwitchCase(
+          switchCase.expressions.map(clone).toList(),
+          new List<int>.from(switchCase.expressionOffsets),
+          null);
     }
     return new SwitchStatement(
         clone(node.expression), node.cases.map(clone).toList());