[Issue 19785] top level const types in function parameters should not mangle as const

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=19785

--- Comment #3 from Walter Bright <bugzilla at digitalmars.com> ---
(In reply to ag0aep6g from comment #1)
> I suppose these should also mangle the same then:

Yes.

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