add test for where clauses mentioning const params

src/test/ui/const-generics/where-clauses.rs

@@ -0,0 +1,35 @@
+// check-pass
+// revisions: full min
+#![cfg_attr(full, feature(const_generics))]
+#![cfg_attr(full, allow(incomplete_features))]
+#![cfg_attr(min, feature(min_const_generics))]
+
+trait Bar<const N: usize> { fn bar() {} }
+trait Foo<const N: usize>: Bar<N> {}
+
+fn test<T, const N: usize>() where T: Foo<N> {
+    <T as Bar<N>>::bar();
+}
+
+struct Faz<const N: usize>;
+
+impl<const N: usize> Faz<N> {
+    fn test<T>() where T: Foo<N> {
+        <T as Bar<N>>::bar()
+    }
+}
+
+trait Fiz<const N: usize> {
+    fn fiz<T>() where T: Foo<N> {
+        <T as Bar<N>>::bar();
+    }
+}
+
+impl<const N: usize> Bar<N> for u8 {}
+impl<const N: usize> Foo<N> for u8 {}
+impl<const N: usize> Fiz<N> for u8 {}
+fn main() {
+    test::<u8, 13>();
+    Faz::<3>::test::<u8>();
+    <u8 as Fiz<13>>::fiz::<u8>();
+}