new handleInvalidTopLevelDeclaration event in fasta parser

pkg/front_end/testcases/regress/issue_29982.dart.strong.expect

Index: pkg/front_end/testcases/regress/issue_29982.dart.strong.expect
diff --git a/pkg/front_end/testcases/regress/issue_29982.dart.strong.expect b/pkg/front_end/testcases/regress/issue_29982.dart.strong.expect
index 81eac886bfeca7ec930a4e88008e57e34acffd3f..0b5e4c4a57693d8971ccad14d5990464468aeef1 100644
--- a/pkg/front_end/testcases/regress/issue_29982.dart.strong.expect
+++ b/pkg/front_end/testcases/regress/issue_29982.dart.strong.expect
@@ -2,6 +2,5 @@ library;
 import self as self;
 
 static method main() → dynamic {
-  throw "pkg/front_end/testcases/regress/issue_29982.dart:9:1: Error: Expected a declaration, but got '''.\n\n^";
+  throw "pkg/front_end/testcases/regress/issue_29982.dart:7:17: Error: Expected ']' before this.\n  print('\${eh[\u0233h']}');\n                ^";
 }
-