[Issue 24291] ImportC: support computed goto

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=24291

--- Comment #9 from Walter Bright <bugzilla at digitalmars.com> ---
At least I can get you a better error message:

https://github.com/dlang/dmd/pull/15967

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