Revert "Auto merge of #39485 - canndrew:inference-fix-39297, r=nikomatsakis"

This reverts commit dc0bb3f283, reversing
changes made to e879aa43ef.

This is a temporary step intended to fix regressions. A more
comprehensive fix for type inference and dead-code is in the works.

src/test/compile-fail/issue-10176.rs

@@ -0,0 +1,19 @@
+// Copyright 2014 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 f() -> isize {
+    (return 1, return 2)
+//~^ ERROR mismatched types
+//~| expected type `isize`
+//~| found type `(_, _)`
+//~| expected isize, found tuple
+}
+
+fn main() {}

src/test/compile-fail/issue-5500.rs

@@ -0,0 +1,17 @@
+// Copyright 2013 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() {
+    &panic!()
+    //~^ ERROR mismatched types
+    //~| expected type `()`
+    //~| found type `&_`
+    //~| expected (), found reference
+}