add test for ICE failed to resolve instance for <[f32; 2] as CrossProduct

Fixes #111667

Author: matthiaskrgr

tests/ui/const-generics/generic_const_exprs/failed-to-resolve-instance-ice-111667.rs

@@ -0,0 +1,18 @@
+// issue rust-lang/rust#111667
+// ICE failed to resolve instance for <[f32; 2] as CrossProduct ..
+//@ check-pass
+
+#![feature(generic_const_exprs)]
+#![allow(incomplete_features)]
+
+pub trait CrossProduct<'a, T, R> {
+    fn cross(&'a self, t: &'a T) -> R;
+}
+
+impl<'a, T, U, const N: usize> CrossProduct<'a, [U; N], [(&'a T, &'a U); N * N]> for [T; N] {
+    fn cross(&'a self, us: &'a [U; N]) -> [(&'a T, &'a U); N * N] {
+        std::array::from_fn(|i| (&self[i / N], &us[i % N]))
+    }
+}
+
+pub fn main() {}