properly set the typeinfo after a successful TValue.TryCast as the internal Conv* routines don't

Author: sglienke

Source/Base/Spring.pas

@@ -6658,6 +6658,8 @@ function TValueHelper.TryCast(ATypeInfo: PTypeInfo;
         Exit(False);
       end;
   Result := TValueHack(Self).TryCast(ATypeInfo, AResult);
+  if Result then
+    TValueData(AResult).FTypeInfo := ATypeInfo;
 end;