Add regression test for issue 47215.

Author: pnkfelix

src/test/ui/borrowck/issue-47215-ice-from-drop-elab.nll.stderr

@@ -0,0 +1,12 @@
+error[E0507]: cannot move out of static item
+  --> $DIR/issue-47215-ice-from-drop-elab.rs:17:21
+   |
+LL |         let mut x = X; //~ ERROR cannot move out of thread-local static item [E0507]
+   |                     ^
+   |                     |
+   |                     cannot move out of static item
+   |                     help: consider borrowing here: `&X`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0507`.

src/test/ui/borrowck/issue-47215-ice-from-drop-elab.rs

@@ -0,0 +1,20 @@
+// rust-lang/rust#47215: at one time, the compiler categorized
+// thread-local statics as a temporary rvalue, as a way to enforce
+// that they are only valid for a given lifetime.
+//
+// The problem with this is that you cannot move out of static items,
+// but you *can* move temporary rvalues. I.e., the categorization
+// above only solves half of the problem presented by thread-local
+// statics.
+
+#![feature(thread_local)]
+
+#[thread_local]
+static mut X: ::std::sync::atomic::AtomicUsize = ::std::sync::atomic::ATOMIC_USIZE_INIT;
+
+fn main() {
+    unsafe {
+        let mut x = X; //~ ERROR cannot move out of thread-local static item [E0507]
+        let _y = x.get_mut();
+    }
+}

src/test/ui/borrowck/issue-47215-ice-from-drop-elab.stderr

@@ -0,0 +1,12 @@
+error[E0507]: cannot move out of thread-local static item
+  --> $DIR/issue-47215-ice-from-drop-elab.rs:17:21
+   |
+LL |         let mut x = X; //~ ERROR cannot move out of thread-local static item [E0507]
+   |                     ^
+   |                     |
+   |                     cannot move out of thread-local static item
+   |                     help: consider using a reference instead: `&X`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0507`.