[Issue 20233] opDispatch hides alias this properties

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=20233

--- Comment #5 from Max Samukha <maxsamukha at gmail.com> ---
'alias this' is irrelevant. The original test case fails because the array's
.ptr property is called as a function. See the example in my previous comment
(there was a typo: "apply" -> "to apply").

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