Auto merge of #26859 - arielb1:const-deref-again, r=eddyb

Fixes #25901 

r? @eddyb

src/test/compile-fail/issue-25901.rs

@@ -0,0 +1,23 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+struct A;
+struct B;
+
+static S: &'static B = &A; //~ ERROR user-defined dereference operators
+
+use std::ops::Deref;
+
+impl Deref for A {
+    type Target = B;
+    fn deref(&self)->&B { static B_: B = B; &B_ }
+}
+
+fn main(){}