Support multiple categories per message.

pkg/compiler/lib/src/diagnostics/generated/shared_messages.dart

Index: pkg/compiler/lib/src/diagnostics/generated/shared_messages.dart
diff --git a/pkg/compiler/lib/src/diagnostics/generated/shared_messages.dart b/pkg/compiler/lib/src/diagnostics/generated/shared_messages.dart
index 13d4c9509a2384f74f6c321661f1ca5b073b2c92..3550e5a00b7845bf30565f610eab620ef00517ac 100644
--- a/pkg/compiler/lib/src/diagnostics/generated/shared_messages.dart
+++ b/pkg/compiler/lib/src/diagnostics/generated/shared_messages.dart
@@ -120,4 +120,19 @@ const Map<MessageKind, MessageTemplate> TEMPLATES = const <MessageKind, MessageT
         """,
     ]
   ),  // Generated. Don't edit.
+  MessageKind.NOT_ASSIGNABLE: const MessageTemplate(
+    MessageKind.NOT_ASSIGNABLE,
+    "'#{fromType}' is not assignable to '#{toType}'."  ),  // Generated. Don't edit.
+  MessageKind.FORIN_NOT_ASSIGNABLE: const MessageTemplate(
+    MessageKind.FORIN_NOT_ASSIGNABLE,
+    "The element type '#{currentType}' of '#{expressionType}' is not assignable to '#{elementType}'.",
+    examples: const [
+      r"""
+        main() {
+          List<int> list = <int>[1, 2];
+          for (String x in list) x;
+        }
+        """,
+    ]
+  ),  // Generated. Don't edit.
 };