[Issue 18269] Inconsistent of delegate @system attribute

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=18269

--- Comment #1 from hsteoh at quickfur.ath.cx ---
P.S. This is a blocker for Phobos PR: https://github.com/dlang/phobos/pull/5797

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