Add 77708

Issue: rust-lang/rust#77708

Author: fanninpm

ices/77708.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+rustc --edition 2018 -C incremental=foo --crate-type lib - <<'EOF'
+#![feature(const_generics, const_evaluatable_checked)]
+#![allow(incomplete_features)]
+use core::{convert::TryFrom, num::NonZeroUsize};
+
+struct A<const N: NonZeroUsize>([u8; N.get()]) where [u8; N.get()]: Sized;
+
+impl<'a, const N: NonZeroUsize> TryFrom<&'a [u8]> for A<N> where [u8; N.get()]: Sized {
+	type Error = ();
+	fn try_from(slice: &'a [u8]) -> Result<A<N>, ()> {
+		let _x = <&[u8; N.get()] as TryFrom<&[u8]>>::try_from(slice);
+		unimplemented!();
+	}
+}
+EOF