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

pkg/front_end/lib/src/fasta/scanner/utf8_bytes_scanner.dart

Index: pkg/front_end/lib/src/fasta/scanner/utf8_bytes_scanner.dart
diff --git a/pkg/front_end/lib/src/fasta/scanner/utf8_bytes_scanner.dart b/pkg/front_end/lib/src/fasta/scanner/utf8_bytes_scanner.dart
index 042dbf2f06cc32dcda2d24af07ea159e2f6c02e7..79106abb45f623210c8664a4ab63ba524103169a 100644
--- a/pkg/front_end/lib/src/fasta/scanner/utf8_bytes_scanner.dart
+++ b/pkg/front_end/lib/src/fasta/scanner/utf8_bytes_scanner.dart
@@ -79,8 +79,10 @@ class Utf8BytesScanner extends ArrayBasedScanner {
    * array whose last element is '0' to signal the end of the file. If this
    * is not the case, the entire array is copied before scanning.
    */
-  Utf8BytesScanner(this.bytes, {bool includeComments: false})
-      : super(includeComments, numberOfBytesHint: bytes.length) {
+  Utf8BytesScanner(this.bytes,
+      {bool includeComments: false, bool scanGenericMethodComments: false})
+      : super(includeComments, scanGenericMethodComments,
+            numberOfBytesHint: bytes.length) {
     assert(bytes.last == 0);
     // Skip a leading BOM.
     if (containsBomAt(0)) byteOffset += 3;