Rollup merge of #54367 - spastorino:add-thread-local-static-borrow-test, r=pnkfelix

Add regression test for thread local static mut borrows

FIXME(#54366) - We probably shouldn't allow `#[thread_local] static mut` to get a `'static` lifetime, but for now, we should at least test the behavior that `rustc` currently has.

Author: kennytm

src/test/ui/nll/borrowck-thread-local-static-mut-borrow-outlives-fn.rs

@@ -0,0 +1,35 @@
+// Copyright 2016 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.
+//
+// run-pass
+//
+// FIXME(#54366) - We probably shouldn't allow #[thread_local] static mut to get a 'static lifetime.
+
+#![feature(nll)]
+#![feature(thread_local)]
+
+#[thread_local]
+static mut X1: u64 = 0;
+
+struct S1 {
+    a: &'static mut u64,
+}
+
+impl S1 {
+    fn new(_x: u64) -> S1 {
+        S1 {
+            a: unsafe { &mut X1 },
+        }
+    }
+}
+
+fn main() {
+    S1::new(0).a;
+}