Consistently normalize fn types after erasing lifetimes.

Fixes #23406.
Fixes #23958.
Fixes #29832.

src/test/run-pass/issue-23406.rs

@@ -0,0 +1,23 @@
+// 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.
+
+trait Inner {
+    type T;
+}
+
+impl<'a> Inner for &'a i32 {
+    type T = i32;
+}
+
+fn f<'a>(x: &'a i32) -> <&'a i32 as Inner>::T {
+    *x
+}
+
+fn main() {}

src/test/run-pass/issue-23598.rs

@@ -0,0 +1,22 @@
+// 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.
+
+trait Collection where for<'a> &'a Self: IntoIterator {
+    fn my_iter(&self) -> <&Self as IntoIterator>::IntoIter {
+        self.into_iter()
+    }
+}
+
+impl<T> Collection for [T] { }
+
+fn main() {
+    let v = [0usize];
+    let _ = v.my_iter();
+}