[Issue 18287] several std.math functions no longer work with alias this

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=18287

hsteoh at quickfur.ath.cx changed:

           What    |Removed                     |Added
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                 CC|                            |hsteoh at quickfur.ath.cx

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