Simplify the foldingRanges fix

Refs #1276

Author: reznikmm

source/ada/lsp-ada_documents.adb

@@ -830,13 +830,6 @@ package body LSP.Ada_Documents is
       procedure Store_Span (Span : LSP.Structures.A_Range);
       --  Include Span to the result .
 
-      function Traverse_Node
-        (Node  : Ada_Node;
-         Visit : access function (Node : Ada_Node'Class) return Visit_Status)
-           return Visit_Status;
-      --  The same as Libadalang.Analysis.Traverse, but without raising
-      --  exception on a null node.
-
       -----------
       -- Parse --
       -----------
@@ -1014,53 +1007,15 @@ package body LSP.Ada_Documents is
          end if;
       end Store_Span;
 
-      -------------------
-      -- Traverse_Node --
-      -------------------
-
-      function Traverse_Node
-        (Node  : Ada_Node;
-         Visit : access function (Node : Ada_Node'Class) return Visit_Status)
-           return Visit_Status
-      is
-         Status : Visit_Status := Into;
-      begin
-         if not Node.Is_Null then
-            Status := Visit (Node);
-            --  Skip processing the child nodes if the returned status is Over
-            --  or Stop. In the former case the previous call to Visit has
-            --  taken care of processing the needed childs, and in the latter
-            --  case we must immediately stop processing the tree.
-            if Status = Into then
-               for I in 1 .. Children_Count (Node) loop
-                  declare
-                     Cur_Child : constant Ada_Node :=
-                       Child (Node, I);
-                  begin
-                     if not Cur_Child.Is_Null then
-                        Status := Traverse_Node (Cur_Child, Visit);
-                        exit when Status /= Into;
-                     end if;
-                  end;
-               end loop;
-            end if;
-         end if;
-
-         if Status = Stop then
-            return Stop;
-            --  At this stage the Over status has no sense and we just continue
-            --  processing the tree.
-         else
-            return Into;
-         end if;
-      end Traverse_Node;
-
       Token  : Token_Reference;
       Span   : LSP.Structures.A_Range;
-      Ignore : constant Visit_Status :=
-        Traverse_Node (Self.Unit (Context).Root, Parse'Access);
+      Root   : constant Ada_Node'Class := Self.Unit (Context).Root;
 
    begin
+      if not Root.Is_Null then
+         Traverse (Root, Parse'Access);
+      end if;
+
       if not Comments then
          --  do not process comments
          return;