[Issue 17065] [REG2.072] Unique does not work with private members

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=17065

--- Comment #7 from dransic at gmail.com ---
std.experimental.typecons.Final is also affected, since its implementation uses
Proxy the same way. 

I should probably change the title for a more general one.

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