fix #2380

fix #2381

TestSuite/errors/err0392.pas

@@ -0,0 +1,14 @@
+type
+  
+  Fixer<TFixer> = class
+   where TFixer: record;
+    
+    procedure p1;
+    begin
+      var a: TFixer;
+      var b := a <> nil;
+    end;
+    
+  end;
+  
+begin end.

TestSuite/where14.pas

@@ -0,0 +1,21 @@
+type
+  
+  Fixer<TFixer> = class
+  where TFixer: Fixer<TFixer>;
+    
+    procedure p1;
+    begin
+      var a: TFixer;
+      assert(a = nil);
+      var o := self as object;
+    end;
+    
+  end;
+  
+  DerFixer = class(Fixer<DerFixer>)
+  end;
+  
+begin 
+ var obj := new DerFixer();
+ obj.p1;
+end.

TreeConverter/TreeRealization/generics.cs

@@ -309,6 +309,8 @@ namespace PascalABCCompiler.TreeRealization
             //Определяем базовый тип
             type_node btype = determine_type(
                 original.base_type, param_types, false);
+            if (btype == null)
+                btype = SystemLibrary.SystemLibrary.object_type;
             instance.SetBaseTypeIgnoringScope(btype);
             
             //instance._scope = new SymbolTable.GenericTypeInstanceScope(instance, instance.original_generic.Scope, btype.Scope);

TreeConverter/TreeRealization/type_table.cs

@@ -278,7 +278,12 @@ namespace PascalABCCompiler.TreeRealization
                     }
                     if (tn.is_generic_parameter)
                     {
-                        return (tn.is_class || tn.base_type != SystemLibrary.SystemLibrary.object_type && tn.base_type.is_class);
+                        if (tn.is_class)
+                            return true;
+                        if (tn.base_type.is_value || tn.is_value_type)
+                            return false;
+                        return true;
+                        //return (tn.is_class || tn.base_type != SystemLibrary.SystemLibrary.object_type && tn.base_type.is_class);
                     }
                     else if (tn is ref_type_node)
                     {