Auto merge of #41965 - Mark-Simulacrum:rollup, r=Mark-Simulacrum

Rollup of 15 pull requests

- Successful merges: #41820, #41860, #41876, #41896, #41912, #41916, #41918, #41921, #41923, #41934, #41935, #41940, #41942, #41943, #41951
- Failed merges:

diff --cc src/librustc_errors/lib.rs
index 0f2e1669a47ad5502cb22d4ce7f2b422c432463a,e1ec23479ab8a7ef84249db60c626b04a116787c..7a561e3a9703f82623fa80f28de306a8e9a9882b
--- 1/src/librustc_errors/lib.rs
--- 2/src/librustc_errors/lib.rs
+++ b/src/librustc_errors/lib.rs
@@@ -18,13 -19,12 +18,14 @@@
  
  #![feature(custom_attribute)]
  #![allow(unused_attributes)]
 -#![feature(rustc_private)]
 -#![feature(staged_api)]
  #![feature(range_contains)]
  #![feature(libc)]
+ #![feature(conservative_impl_trait)]
  
 +#![cfg_attr(stage0, unstable(feature = "rustc_private", issue = "27812"))]
 +#![cfg_attr(stage0, feature(rustc_private))]
 +#![cfg_attr(stage0, feature(staged_api))]
 +
  extern crate term;
  extern crate libc;
  extern crate serialize as rustc_serialize;

diff --cc src/librustc_resolve/lib.rs
Simple merge

diff --cc src/librustc_trans/lib.rs
Simple merge