Format libstd with rustfmt

This commit applies rustfmt with rust-lang/rust's default settings to
files in src/libstd *that are not involved in any currently open PR* to
minimize merge conflicts. THe list of files involved in open PRs was
determined by querying GitHub's GraphQL API with this script:
https://gist.github.com/dtolnay/aa9c34993dc051a4f344d1b10e4487e8

With the list of files from the script in outstanding_files, the
relevant commands were:

    $ find src/libstd -name '*.rs' \
        | xargs rustfmt --edition=2018 --unstable-features --skip-children
    $ rg libstd outstanding_files | xargs git checkout --

Repeating this process several months apart should get us coverage of
most of the rest of libstd.

To confirm no funny business:

    $ git checkout $THIS_COMMIT^
    $ git show --pretty= --name-only $THIS_COMMIT \
        | xargs rustfmt --edition=2018 --unstable-features --skip-children
    $ git diff $THIS_COMMIT  # there should be no difference

1 files changed, 5 insertions, 12 deletions

diff --git a/src/libstd/sync/mpsc/blocking.rs b/src/libstd/sync/mpsc/blocking.rs
index 6eacfaec253..d34de6a4fac 100644
--- a/src/libstd/sync/mpsc/blocking.rs
+++ b/src/libstd/sync/mpsc/blocking.rs
@@ -1,9 +1,9 @@
 //! Generic support for building blocking abstractions.
 
-use crate::thread::{self, Thread};
+use crate::mem;
 use crate::sync::atomic::{AtomicBool, Ordering};
 use crate::sync::Arc;
-use crate::mem;
+use crate::thread::{self, Thread};
 use crate::time::Instant;
 
 struct Inner {
@@ -28,16 +28,9 @@ impl !Send for WaitToken {}
 impl !Sync for WaitToken {}
 
 pub fn tokens() -> (WaitToken, SignalToken) {
-    let inner = Arc::new(Inner {
-        thread: thread::current(),
-        woken: AtomicBool::new(false),
-    });
-    let wait_token = WaitToken {
-        inner: inner.clone(),
-    };
-    let signal_token = SignalToken {
-        inner,
-    };
+    let inner = Arc::new(Inner { thread: thread::current(), woken: AtomicBool::new(false) });
+    let wait_token = WaitToken { inner: inner.clone() };
+    let signal_token = SignalToken { inner };
     (wait_token, signal_token)
 }