Auto merge of #27261 - arielb1:drop-sanity-check, r=pnkfelix

This fixes multiple bugs, and as several of these are soundness issue, is a [breaking-change].

r? @pnkfelix

src/test/compile-fail/dropck_misc_variants.rs

@@ -0,0 +1,47 @@
+// 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.
+
+// check that dropck does the right thing with misc. Ty variants
+
+use std::fmt;
+struct NoisyDrop<T: fmt::Debug>(T);
+impl<T: fmt::Debug> Drop for NoisyDrop<T> {
+    fn drop(&mut self) {
+        let _ = vec!["0wned"];
+        println!("dropping {:?}", self.0)
+    }
+}
+
+trait Associator {
+    type As;
+}
+impl<T: fmt::Debug> Associator for T {
+    type As = NoisyDrop<T>;
+}
+struct Wrap<A: Associator>(<A as Associator>::As);
+
+fn projection() {
+    let (_w, bomb);
+    bomb = vec![""];
+    _w = Wrap::<&[&str]>(NoisyDrop(&bomb));
+    //~^ ERROR `bomb` does not live long enough
+}
+
+fn closure() {
+    let (_w,v);
+    v = vec![""];
+    _w = {
+        let u = NoisyDrop(&v);
+        //~^ ERROR `v` does not live long enough
+        move || u.0.len()
+    };
+}
+
+fn main() { closure(); projection() }