[Issue 18149] Add a compiler trait to detect if a function is @disable

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=18149

Basile B. <b2.temp at gmx.com> changed:

           What    |Removed                     |Added
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             Blocks|                            |11747


Referenced Issues:

https://issues.dlang.org/show_bug.cgi?id=11747
[Issue 11747] Better error message with @disabled toString
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