Run cleanup for base struct in functional struct update expressions

Fixes #17302.

src/test/run-pass/issue-17302.rs

@@ -0,0 +1,34 @@
+// 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.
+
+static mut DROPPED: [bool, ..2] = [false, false];
+
+struct A(uint);
+struct Foo { _a: A, _b: int }
+
+impl Drop for A {
+    fn drop(&mut self) {
+        let A(i) = *self;
+        unsafe { DROPPED[i] = true; }
+    }
+}
+
+fn main() {
+    {
+        Foo {
+            _a: A(0),
+            ..Foo { _a: A(1), _b: 2 }
+        };
+    }
+    unsafe {
+        assert!(DROPPED[0]);
+        assert!(DROPPED[1]);
+    }
+}