rustc_typeck: consolidate adjustment composition

Fixes #41213.

src/test/run-pass/issue-41213.rs

@@ -0,0 +1,32 @@
+// 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.
+
+enum A {
+    A1,
+    A2,
+    A3,
+}
+
+enum B {
+    B1(String, String),
+    B2(String, String),
+}
+
+fn main() {
+    let a = A::A1;
+    loop {
+        let _ctor = match a {
+            A::A3 => break,
+            A::A1 => B::B1,
+            A::A2 => B::B2,
+        };
+        break;
+    }
+}