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

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libstd/sys/sgx/ext/mod.rs b/src/libstd/sys/sgx/ext/mod.rs
index 51b2659da83..258ad3cd218 100644
--- a/src/libstd/sys/sgx/ext/mod.rs
+++ b/src/libstd/sys/sgx/ext/mod.rs
@@ -1,5 +1,5 @@
 #![unstable(feature = "sgx_platform", issue = "56975")]
 
 pub mod arch;
-pub mod io;
 pub mod ffi;
+pub mod io;