improve fasta unterminated string recovery

pkg/front_end/test/scanner_replacement_test.dart

Index: pkg/front_end/test/scanner_replacement_test.dart
diff --git a/pkg/front_end/test/scanner_replacement_test.dart b/pkg/front_end/test/scanner_replacement_test.dart
index b0e39cb4df7d592945fbff5b2e652b76eba304f7..7a0c815f365d0ebc0a52262da3c522296146846c 100644
--- a/pkg/front_end/test/scanner_replacement_test.dart
+++ b/pkg/front_end/test/scanner_replacement_test.dart
@@ -192,48 +192,6 @@ class ScannerTest_Replacement extends ScannerTestBase {
 
   @override
   @failingTest
-  void test_string_multi_unterminated() {
-    // See defaultRecoveryStrategy recoverString
-    super.test_string_multi_unterminated();
-  }
-
-  @override
-  @failingTest
-  void test_string_multi_unterminated_interpolation_block() {
-    // See defaultRecoveryStrategy recoverString
-    super.test_string_multi_unterminated_interpolation_block();
-  }
-
-  @override
-  @failingTest
-  void test_string_multi_unterminated_interpolation_identifier() {
-    // See defaultRecoveryStrategy recoverString
-    super.test_string_multi_unterminated_interpolation_identifier();
-  }
-
-  @override
-  @failingTest
-  void test_string_raw_multi_unterminated() {
-    // See defaultRecoveryStrategy recoverString
-    super.test_string_raw_multi_unterminated();
-  }
-
-  @override
-  @failingTest
-  void test_string_raw_simple_unterminated_eof() {
-    // See defaultRecoveryStrategy recoverString
-    super.test_string_raw_simple_unterminated_eof();
-  }
-
-  @override
-  @failingTest
-  void test_string_raw_simple_unterminated_eol() {
-    // See defaultRecoveryStrategy recoverString
-    super.test_string_raw_simple_unterminated_eol();
-  }
-
-  @override
-  @failingTest
   void test_string_simple_interpolation_missingIdentifier() {
     // See defaultRecoveryStrategy recoverStringInterpolation
     super.test_string_simple_interpolation_missingIdentifier();
@@ -247,34 +205,6 @@ class ScannerTest_Replacement extends ScannerTestBase {
   }
 
   @override
-  @failingTest
-  void test_string_simple_unterminated_eof() {
-    // See defaultRecoveryStrategy recoverString
-    super.test_string_simple_unterminated_eof();
-  }
-
-  @override
-  @failingTest
-  void test_string_simple_unterminated_eol() {
-    // See defaultRecoveryStrategy recoverString
-    super.test_string_simple_unterminated_eol();
-  }
-
-  @override
-  @failingTest
-  void test_string_simple_unterminated_interpolation_block() {
-    // See defaultRecoveryStrategy recoverString
-    super.test_string_simple_unterminated_interpolation_block();
-  }
-
-  @override
-  @failingTest
-  void test_string_simple_unterminated_interpolation_identifier() {
-    // See defaultRecoveryStrategy recoverString
-    super.test_string_simple_unterminated_interpolation_identifier();
-  }
-
-  @override
   void test_unmatched_openers() {
     // fasta inserts missing closers except for '<'
     var openBrace = _scan('{[(<') as analyzer.BeginToken;