Feature: Additon to Dwarf to distinguish between scoped and non-scoped enums

Code like

  {$SCOPEDENUMS ON}
    TUseBoolStrs = (False, True);
  {$SCOPEDENUMS OFF}

produces the same dwarf, as code where the enum is defined with {$SCOPEDENUMS OFF}.

However, if the debugger looks up a symbol that happens to be the same name as one of the enum members, then the debugger needs to know if the enum members should be found or not.

If need, fpc may have to add a custom dwarf tag for that.