Gag errors mentioning _d_array{,set}ctor

[teodutu]

While working on #13116, I made the mistake of letting nothrow and purity errors leak the internal lowering to _d_array{,set}ctor. This is bad practice and is confusing to the user. This PR rectifies that mistake.

[dlang-bot]

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Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + dmd#13476"

[ibuclaw]

This caused a regression https://issues.dlang.org/show_bug.cgi?id=22659