Java: add ForStmt wrapper class

Author: owen-mc

java/ql/lib/semmle/code/java/ControlFlowGraph.qll

@@ -84,7 +84,13 @@ private module Ast implements AstSig<Location> {
 
   class DoStmt = J::DoStmt;
 
-  class ForStmt = J::ForStmt;
+  final private class FinalForStmt = J::ForStmt;
+
+  class ForStmt extends FinalForStmt {
+    AstNode getInit(int index) { result = super.getInit(index) }
+
+    AstNode getUpdate(int index) { result = super.getUpdate(index) }
+  }
 
   final private class FinalEnhancedForStmt = J::EnhancedForStmt;