[kernel] Fix assert message.

pkg/kernel/lib/ast.dart

Index: pkg/kernel/lib/ast.dart
diff --git a/pkg/kernel/lib/ast.dart b/pkg/kernel/lib/ast.dart
index eb988a582c60476921b12ad5dee5ed133606e031..9710ebae31411ac902875d92ef6f435c90e47a31 100644
--- a/pkg/kernel/lib/ast.dart
+++ b/pkg/kernel/lib/ast.dart
@@ -3161,6 +3161,8 @@ class EmptyStatement extends Statement {
 class AssertStatement extends Statement {
   Expression condition;
   Expression message; // May be null.
+  int conditionStartOffset;
+  int conditionEndOffset;
 
   AssertStatement(this.condition, [this.message]) {

[ahe, 2017/06/16 07:41:51]

Make message a named argument and the offsets as named arguments as well?

[jensj, 2017/06/16 07:43:29]

Will do.

     condition?.parent = this;