[Issue 19605] invalid forward reference error when getting the `.sizeof` of an opaque enum

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=19605

Basile-z <b2.temp at gmx.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|invalid forward reference   |invalid forward reference
                   |error when getting the      |error when getting the
                   |`.sizeof` if an opaque enum |`.sizeof` of an opaque enum

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