Only need NameLookup for the ASTScope interface class.

Author: David Ungar

Diff for: lib/FrontendTool/FrontendTool.cpp

@@ -26,13 +26,13 @@
 #include "TBD.h"
 
 #include "swift/Subsystems.h"
-#include "swift/AST/ASTScope.h"
 #include "swift/AST/DiagnosticsFrontend.h"
 #include "swift/AST/DiagnosticsSema.h"
 #include "swift/AST/ExperimentalDependencies.h"
 #include "swift/AST/FileSystem.h"
 #include "swift/AST/GenericSignatureBuilder.h"
 #include "swift/AST/IRGenOptions.h"
+#include "swift/AST/NameLookup.h"
 #include "swift/AST/ASTMangler.h"
 #include "swift/AST/ReferencedNameTracker.h"
 #include "swift/AST/TypeRefinementContext.h"