Rollup merge of rust-lang#66497 - Nadrieril:fix-53820, r=varkor

Fix rust-lang#53820

This fixes ICE rust-lang#53820 by being more clever when matching large arrays with slice patterns.
In particular, it avoids treating large arrays like large tuples, and instead reuses the `VarLenSlice` constructor behaviour to only consider as little values as needed.
As a side-effect, such matches also get improved diagnostics, by reporting `[true, ..]` missing instead of `[true, _, _, _, _, _, _, _]`.