Auto merge of #32780 - soltanmm:consider-the-following, r=nikomatsakis

Replace consider_unification_despite_ambiguity with new obligation variant

Is work towards #32730. Addresses part one of #32286. Addresses #24210 and #26046 to some degree.

r? @nikomatsakis

src/test/compile-fail/closure-wrong-kind.rs

@@ -0,0 +1,22 @@
+// 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.
+
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+struct X;
+fn foo<T>(_: T) {}
+fn bar<T: Fn(u32)>(_: T) {}
+
+fn main() {
+    let x = X;
+    let closure = |_| foo(x);  //~ ERROR E0524
+    bar(closure);
+}