fix linking of place projections

projections other than dereferences of `&mut` used to do no linking. Fix
that.

Fixes #46974.

src/test/ui/nll/guarantor-issue-46974.rs

@@ -0,0 +1,31 @@
+// Copyright 2017 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.
+
+// Test that NLL analysis propagates lifetimes correctly through
+// field accesses, Box accesses, etc.
+
+#![feature(nll)]
+
+fn foo(s: &mut (i32,)) -> i32 {
+    let t = &mut *s; // this borrow should last for the entire function
+    let x = &t.0;
+    *s = (2,); //~ ERROR cannot assign to `*s`
+    *x
+}
+
+fn bar(s: &Box<(i32,)>) -> &'static i32 {
+    // FIXME(#46983): error message should be better
+    &s.0 //~ ERROR free region `` does not outlive free region `'static`
+}
+
+fn main() {
+    foo(&mut (0,));
+    bar(&Box::new((1,)));
+}

src/test/ui/nll/guarantor-issue-46974.stderr

@@ -0,0 +1,17 @@
+error[E0506]: cannot assign to `*s` because it is borrowed
+  --> $DIR/guarantor-issue-46974.rs:19:5
+   |
+17 |     let t = &mut *s; // this borrow should last for the entire function
+   |             ------- borrow of `*s` occurs here
+18 |     let x = &t.0;
+19 |     *s = (2,); //~ ERROR cannot assign to `*s`
+   |     ^^^^^^^^^ assignment to borrowed `*s` occurs here
+
+error: free region `` does not outlive free region `'static`
+  --> $DIR/guarantor-issue-46974.rs:25:5
+   |
+25 |     &s.0 //~ ERROR free region `` does not outlive free region `'static`
+   |     ^^^^
+
+error: aborting due to 2 previous errors
+