Add 'scanGenericMethodComments' parameter to constructors and scan() functions.

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 f126bd5a60bdcf3dba33c13851793c168f382c28..bab9d0f7809026d49ecb77db9150d99e72e22222 100644
--- a/pkg/front_end/test/scanner_replacement_test.dart
+++ b/pkg/front_end/test/scanner_replacement_test.dart
@@ -35,17 +35,12 @@ class ScannerTest_Replacement extends ScannerTest {
   analyzer.Token scanWithListener(String source, ErrorListener listener,
       {bool genericMethodComments: false,
       bool lazyAssignmentOperators: false}) {
-    if (genericMethodComments) {
-      // Fasta doesn't support generic method comments.
-      // TODO(danrubel): once the analyzer toolchain no longer needs generic
-      // method comments, remove tests that exercise them.
-      fail('No generic method comment support in Fasta');
-    }
     // Note: Fasta always supports lazy assignment operators (`&&=` and `||=`),
     // so we can ignore the `lazyAssignmentOperators` flag.
     // TODO(danrubel): once lazyAssignmentOperators are fully supported by
     // Dart, remove this flag.
-    fasta.ScannerResult result = fasta.scanString(source, includeComments: true,
+    fasta.ScannerResult result = fasta.scanString(source,
+        includeComments: true, scanGenericMethodComments: genericMethodComments,
         recover: ((List<int> bytes, fasta.Token tokens, List<int> lineStarts) {
       // perform recovery as a separate step
       // so that the token stream can be validated before and after recovery
@@ -78,22 +73,6 @@ class ScannerTest_Replacement extends ScannerTest {
     super.test_bar_bar_eq();
   }
 
-  @override
-  @failingTest
-  void test_comment_generic_method_type_assign() {
-    // TODO(paulberry,ahe): Fasta scanner doesn't support generic comment
-    // syntax.
-    super.test_comment_generic_method_type_assign();
-  }
-
-  @override
-  @failingTest
-  void test_comment_generic_method_type_list() {
-    // TODO(paulberry,ahe): Fasta scanner doesn't support generic comment
-    // syntax.
-    super.test_comment_generic_method_type_list();
-  }
-
   void _assertOpenClosePair(String source) {
     fasta.BeginGroupToken open = _scan(source);
     fasta.Token close = open.next;