Add a test for a function taking a const param array as an argument

src/test/ui/const-generics/fn-taking-const-generic-array.rs

@@ -0,0 +1,16 @@
+// run-pass
+
+#![feature(const_generics)]
+//~^ WARN the feature `const_generics` is incomplete and may cause the compiler to crash
+
+use std::fmt::Display;
+
+fn print_slice<T: Display, const N: usize>(slice: &[T; N]) {
+    for x in slice.iter() {
+        println!("{}", x);
+    }
+}
+
+fn main() {
+    print_slice(&[1, 2, 3]);
+}

src/test/ui/const-generics/fn-taking-const-generic-array.stderr

@@ -0,0 +1,6 @@
+warning: the feature `const_generics` is incomplete and may cause the compiler to crash
+  --> $DIR/fn-taking-const-generic-array.rs:3:12
+   |
+LL | #![feature(const_generics)]
+   |            ^^^^^^^^^^^^^^
+