Auto merge of #45785 - arielb1:unsafe-fixes, r=eddyb

fixes to MIR effectck

r? @eddyb

beta-nominating because regression (MIR effectck is new)

src/test/compile-fail/issue-45087-unreachable-unsafe.rs

@@ -0,0 +1,15 @@
+// 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.
+
+fn main() {
+    return;
+    *(1 as *mut u32) = 42;
+    //~^ ERROR dereference of raw pointer requires unsafe
+}

src/test/compile-fail/issue-45729-unsafe-in-generator.rs

@@ -0,0 +1,19 @@
+// 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.
+
+#![feature(generators)]
+
+fn main() {
+    let _ = || {
+        *(1 as *mut u32) = 42;
+        //~^ ERROR dereference of raw pointer requires unsafe
+        yield;
+    };
+}