Feature request: Implement {$legacyifend on/off}
<h3><details><summary>Original Reporter info from Mantis: <small>Thaddy</small></summary><small>
- **Reporter name:** Thaddy de Koning
</small></details></h3>
## Description:
From Delphi XE4, there is a directive {$LEGACYIFEND ON/OFF}<br/>
If it is ON, {$IF}{$IFEND} is enforced<br/>
if it is OFF both {$ENDIF} and {$IFEND} is allowed for {$IF}, as it is now for FPC.<br/>
Since many prefer the enforced behavior (at least I do for clarity, maybe this can be implemented.
## Mantis conversion info:
- **Mantis ID:** 37676
- **OS:** All
- **OS Build:** All
- **Build:** 46729
- **Platform:** All
- **Version:** 3.3.1
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