Format libstd/sys with rustfmt

This commit applies rustfmt with rust-lang/rust's default settings to
files in src/libstd/sys *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/sys -name '*.rs' \
        | xargs rustfmt --edition=2018 --unstable-features --skip-children
    $ rg libstd/sys outstanding_files | xargs git checkout --

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

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

src/libstd/sys/unix/ext/process.rs

@@ -4,10 +4,10 @@
 
 use crate::ffi::OsStr;
 use crate::io;
-use crate::os::unix::io::{FromRawFd, RawFd, AsRawFd, IntoRawFd};
+use crate::os::unix::io::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
 use crate::process;
 use crate::sys;
-use crate::sys_common::{AsInnerMut, AsInner, FromInner, IntoInner};
+use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
 
 /// Unix-specific extensions to the [`process::Command`] builder.
 ///
@@ -56,7 +56,8 @@ pub trait CommandExt {
     /// locations may not appear where intended.
     #[stable(feature = "process_pre_exec", since = "1.34.0")]
     unsafe fn pre_exec<F>(&mut self, f: F) -> &mut process::Command
-        where F: FnMut() -> io::Result<()> + Send + Sync + 'static;
+    where
+        F: FnMut() -> io::Result<()> + Send + Sync + 'static;
 
     /// Schedules a closure to be run just before the `exec` function is
     /// invoked.
@@ -68,7 +69,8 @@ pub trait CommandExt {
     #[stable(feature = "process_exec", since = "1.15.0")]
     #[rustc_deprecated(since = "1.37.0", reason = "should be unsafe, use `pre_exec` instead")]
     fn before_exec<F>(&mut self, f: F) -> &mut process::Command
-        where F: FnMut() -> io::Result<()> + Send + Sync + 'static
+    where
+        F: FnMut() -> io::Result<()> + Send + Sync + 'static,
     {
         unsafe { self.pre_exec(f) }
     }
@@ -111,7 +113,8 @@ pub trait CommandExt {
     /// default executable path.
     #[unstable(feature = "process_set_argv0", issue = "66510")]
     fn arg0<S>(&mut self, arg: S) -> &mut process::Command
-        where S: AsRef<OsStr>;
+    where
+        S: AsRef<OsStr>;
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -127,7 +130,8 @@ impl CommandExt for process::Command {
     }
 
     unsafe fn pre_exec<F>(&mut self, f: F) -> &mut process::Command
-        where F: FnMut() -> io::Result<()> + Send + Sync + 'static
+    where
+        F: FnMut() -> io::Result<()> + Send + Sync + 'static,
     {
         self.as_inner_mut().pre_exec(Box::new(f));
         self
@@ -138,7 +142,8 @@ impl CommandExt for process::Command {
     }
 
     fn arg0<S>(&mut self, arg: S) -> &mut process::Command
-        where S: AsRef<OsStr>
+    where
+        S: AsRef<OsStr>,
     {
         self.as_inner_mut().set_arg_0(arg.as_ref());
         self