Move scanner into pkg/front_end/lib/src/scanner.

pkg/analyzer/lib/dart/ast/syntactic_entity.dart

Index: pkg/analyzer/lib/dart/ast/syntactic_entity.dart
diff --git a/pkg/analyzer/lib/dart/ast/syntactic_entity.dart b/pkg/analyzer/lib/dart/ast/syntactic_entity.dart
index bc8271a2a0af13a3443f53341b5c8730eb866eaa..5ab6c7817497db92bb6e936ca1a219f4b5e7f33d 100644
--- a/pkg/analyzer/lib/dart/ast/syntactic_entity.dart
+++ b/pkg/analyzer/lib/dart/ast/syntactic_entity.dart
@@ -4,25 +4,5 @@
 
 library analyzer.dart.ast.syntactic_entity;
 
-/**
- * Interface representing a syntactic entity (either a token or an AST node)
- * which has a location and extent in the source file.
- */
-abstract class SyntacticEntity {
-  /**
-   * Return the offset from the beginning of the file to the character after the
-   * last character of the syntactic entity.
-   */
-  int get end;
-
-  /**
-   * Return the number of characters in the syntactic entity's source range.
-   */
-  int get length;
-
-  /**
-   * Return the offset from the beginning of the file to the first character in
-   * the syntactic entity.
-   */
-  int get offset;
-}
+export 'package:front_end/src/scanner/syntactic_entity.dart'
+    show SyntacticEntity;