Implement shell-style comments and record shebangs as comments.

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

Index: pkg/front_end/lib/src/fasta/scanner/string_scanner.dart
diff --git a/pkg/front_end/lib/src/fasta/scanner/string_scanner.dart b/pkg/front_end/lib/src/fasta/scanner/string_scanner.dart
index 641a678644432bd4891561129bf4d458d38312bd..dab6d70d18a782e52b29edd1031b445db6bb387c 100644
--- a/pkg/front_end/lib/src/fasta/scanner/string_scanner.dart
+++ b/pkg/front_end/lib/src/fasta/scanner/string_scanner.dart
@@ -25,9 +25,10 @@ class StringScanner extends ArrayBasedScanner {
   /** The current offset in [string]. */
   int scanOffset = -1;
 
-  StringScanner(String string, {bool includeComments: false})
+  StringScanner(String string,
+      {bool includeComments: false, bool enableShellStyleComments: false})
       : string = ensureZeroTermination(string),
-        super(includeComments);
+        super(includeComments, enableShellStyleComments);
 
   static String ensureZeroTermination(String string) {
     return (string.isEmpty || string.codeUnitAt(string.length - 1) != 0)