Add some tests for dynamic dropping

Also remove these drop-glue i8 things… They for some reason make these completely non-MIR tests
fail after dyndrop commit which has literally 0 changes around the regular old trans. Wut?

Author: nagisa

src/test/run-fail/mir_dynamic_drops_1.rs

@@ -0,0 +1,41 @@
+// 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.
+#![feature(rustc_attrs)]
+// error-pattern:drop 1
+// error-pattern:drop 2
+use std::io::{self, Write};
+
+
+/// Structure which will not allow to be dropped twice.
+struct Droppable(bool, u32);
+impl Drop for Droppable {
+    fn drop(&mut self) {
+        if self.0 {
+            writeln!(io::stderr(), "{} dropped twice", self.1);
+            ::std::process::exit(1);
+        }
+        writeln!(io::stderr(), "drop {}", self.1);
+        self.0 = true;
+    }
+}
+
+#[rustc_mir]
+fn mir(){
+    let x = Droppable(false, 1);
+    let y = Droppable(false, 2);
+    let mut z = x;
+    let k = y;
+    z = k;
+}
+
+fn main() {
+    mir();
+    panic!();
+}

src/test/run-fail/mir_dynamic_drops_2.rs

@@ -0,0 +1,39 @@
+// 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.
+#![feature(rustc_attrs)]
+// error-pattern:drop 1
+use std::io::{self, Write};
+
+
+/// Structure which will not allow to be dropped twice.
+struct Droppable(bool, u32);
+impl Drop for Droppable {
+    fn drop(&mut self) {
+        if self.0 {
+            writeln!(io::stderr(), "{} dropped twice", self.1);
+            ::std::process::exit(1);
+        }
+        writeln!(io::stderr(), "drop {}", self.1);
+        self.0 = true;
+    }
+}
+
+#[rustc_mir]
+fn mir(d: Droppable){
+    loop {
+        let x = d;
+        break;
+    }
+}
+
+fn main() {
+    mir(Droppable(false, 1));
+    panic!();
+}

src/test/run-fail/mir_dynamic_drops_3.rs

@@ -0,0 +1,43 @@
+// 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.
+#![feature(rustc_attrs)]
+// error-pattern:unwind happens
+// error-pattern:drop 3
+// error-pattern:drop 2
+// error-pattern:drop 1
+use std::io::{self, Write};
+
+
+/// Structure which will not allow to be dropped twice.
+struct Droppable(bool, u32);
+impl Drop for Droppable {
+    fn drop(&mut self) {
+        if self.0 {
+            writeln!(io::stderr(), "{} dropped twice", self.1);
+            ::std::process::exit(1);
+        }
+        writeln!(io::stderr(), "drop {}", self.1);
+        self.0 = true;
+    }
+}
+
+fn may_panic() -> Droppable {
+    panic!("unwind happens");
+}
+
+#[rustc_mir]
+fn mir(d: Droppable){
+    let y = Droppable(false, 2);
+    let x = [Droppable(false, 1), y, d, may_panic()];
+}
+
+fn main() {
+    mir(Droppable(false, 3));
+}