fix #2736

TestSuite/where22.pas

@@ -0,0 +1,22 @@
+type
+  t1<TSelf> = interface
+    where TSelf: t1<TSelf>;
+    function f: integer;
+  end;
+  //Ошибка: Невозможно инстанцировать, так как тип TSelf не реализует интерфейс t1<TSelf>
+  t2<TSelf> = interface(t1<TSelf>)
+    where TSelf: t2<TSelf>;
+    // А если так то работает:
+//    where TSelf: t1<TSelf>, t2<TSelf>;
+  end;
+  
+  TClass = class(t2<TClass>)
+    public function f: integer;
+    begin
+      Result := 1;
+    end;
+  end;
+begin 
+  var obj := new TClass;
+  assert(obj.f = 1);
+end.

TreeConverter/TreeRealization/type_table.cs

@@ -665,6 +665,17 @@ namespace PascalABCCompiler.TreeRealization
                                     break;
                             }
                         }
+                        else if (interf is common_generic_instance_type_node cictn && base_class is common_generic_instance_type_node cbctn)
+                        {
+                            foreach (type_node impltn in cictn.ImplementingInterfaces)
+                            {
+                                if (is_type_or_original_generics_equal(impltn, cbctn))
+                                {
+                                    implements = true;
+                                    break;
+                                }
+                            }
+                        }
                         else if (interf is compiled_type_node ictn && base_class is compiled_type_node bctn)
                         {
                             if (ictn.compiled_type.AssemblyQualifiedName != null && ictn.compiled_type.AssemblyQualifiedName == bctn.compiled_type.AssemblyQualifiedName)