Auto merge of #3711 - saethlin:rustup, r=saethlin

Manual Rustup

This bumps us to a rustc commit that doesn't have the chatty `./miri fmt` reported in https://rust-lang.zulipchat.com/#narrow/stream/269128-miri/topic/.22rewriting.20static.22.20printed.20during.20.2E.2Fmiri.20build

rust-version

@@ -1 +1 @@
-d49994b060684af423339b55769439b2f444a7b9
+c290e9de32e8ba6a673ef125fde40eadd395d170

tests/pass-dep/concurrency/tls_pthread_drop_order.rs

@@ -1,9 +1,9 @@
 //@ignore-target-windows: No pthreads on Windows
 //! Test that pthread_key destructors are run in the right order.
 //! Note that these are *not* used by actual `thread_local!` on Linux! Those use
-//! `thread_local_dtor::register_dtor` from the stdlib instead. In Miri this hits the fallback path
-//! in `register_dtor_fallback`, which uses a *single* pthread_key to manage a thread-local list of
-//! dtors to call.
+//! `destructors::register` from the stdlib instead. In Miri this ends up hitting
+//! the fallback path in `guard::key::enable`, which uses a *single* pthread_key
+//! to manage a thread-local list of dtors to call.
 
 use std::mem;
 use std::ptr;