[kernel] Position on switch expression

pkg/front_end/lib/src/fasta/kernel/body_builder.dart

Index: pkg/front_end/lib/src/fasta/kernel/body_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
index 7a84b26ef8d355126509dbfff59bdec08b7d8271..3dfad08dcf6c4194195480bbee4e1bd919a53f31 100644
--- a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
@@ -2862,7 +2862,8 @@ class BodyBuilder extends ScopeListener<JumpTarget> implements BuilderHelper {
   }
 
   @override
-  void endSwitchBlock(int caseCount, Token beginToken, Token endToken) {
+  void endSwitchBlock(
+      int caseCount, Token beginToken, Token endToken, Token switchKeyword) {
     debugEvent("SwitchBlock");
     List<SwitchCase> cases =
         new List<SwitchCase>.filled(caseCount, null, growable: true);
@@ -2913,7 +2914,8 @@ class BodyBuilder extends ScopeListener<JumpTarget> implements BuilderHelper {
     exitSwitchScope();
     exitLocalScope();
     Expression expression = popForValue();
-    Statement result = new KernelSwitchStatement(expression, cases);
+    Statement result = new KernelSwitchStatement(expression, cases)
+      ..fileOffset = switchKeyword.charOffset;
     if (target.hasUsers) {
       result = new KernelLabeledStatement(result);
       target.resolveBreaks(result);