Auto merge of #4581 - tamird:master, r=alexcrichton
authorbors <bors@rust-lang.org>
Tue, 10 Oct 2017 18:36:48 +0000 (18:36 +0000)
committerbors <bors@rust-lang.org>
Tue, 10 Oct 2017 18:36:48 +0000 (18:36 +0000)
cargo_rustc: remove workaround for fixed upstream issue

Fixed in https://github.com/rust-lang/rust/pull/25411. Also, the
removed code is implicated in test failures observed in
https://github.com/rust-lang/rust/pull/44515.

r? @alexcrichton


Trivial merge