[Issue 20409] Interface parameter conversion inversed - breaking all attributes enforcement

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=20409

--- Comment #1 from Eyal <eyal at weka.io> ---
NOTE: By "strengthen" I mean adding arbitrary attributes like @nogc or pure to
a delegate that does not truly have them.

This bug means D's attribute enforcement, including @safe, is fundamentally
broken.

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