Format libcore with rustfmt

This commit applies rustfmt with default settings to files in
src/libcore *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/libcore -name '*.rs' | xargs rustfmt --edition=2018
    $ rg libcore outstanding_files | xargs git checkout --

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

2 files changed, 23 insertions, 30 deletions

diff --git a/src/libcore/ptr/non_null.rs b/src/libcore/ptr/non_null.rs
index 7599991f0f1..a121389bef3 100644
--- a/src/libcore/ptr/non_null.rs
+++ b/src/libcore/ptr/non_null.rs
@@ -1,11 +1,11 @@
+use crate::cmp::Ordering;
 use crate::convert::From;
-use crate::ops::{CoerceUnsized, DispatchFromDyn};
 use crate::fmt;
 use crate::hash;
 use crate::marker::Unsize;
 use crate::mem;
+use crate::ops::{CoerceUnsized, DispatchFromDyn};
 use crate::ptr::Unique;
-use crate::cmp::Ordering;
 
 // ignore-tidy-undocumented-unsafe
 
@@ -48,12 +48,12 @@ pub struct NonNull<T: ?Sized> {
 /// `NonNull` pointers are not `Send` because the data they reference may be aliased.
 // N.B., this impl is unnecessary, but should provide better error messages.
 #[stable(feature = "nonnull", since = "1.25.0")]
-impl<T: ?Sized> !Send for NonNull<T> { }
+impl<T: ?Sized> !Send for NonNull<T> {}
 
 /// `NonNull` pointers are not `Sync` because the data they reference may be aliased.
 // N.B., this impl is unnecessary, but should provide better error messages.
 #[stable(feature = "nonnull", since = "1.25.0")]
-impl<T: ?Sized> !Sync for NonNull<T> { }
+impl<T: ?Sized> !Sync for NonNull<T> {}
 
 impl<T: Sized> NonNull<T> {
     /// Creates a new `NonNull` that is dangling, but well-aligned.
@@ -91,11 +91,7 @@ impl<T: ?Sized> NonNull<T> {
     #[stable(feature = "nonnull", since = "1.25.0")]
     #[inline]
     pub fn new(ptr: *mut T) -> Option<Self> {
-        if !ptr.is_null() {
-            Some(unsafe { Self::new_unchecked(ptr) })
-        } else {
-            None
-        }
+        if !ptr.is_null() { Some(unsafe { Self::new_unchecked(ptr) }) } else { None }
     }
 
     /// Acquires the underlying `*mut` pointer.
@@ -131,9 +127,7 @@ impl<T: ?Sized> NonNull<T> {
     #[stable(feature = "nonnull_cast", since = "1.27.0")]
     #[inline]
     pub const fn cast<U>(self) -> NonNull<U> {
-        unsafe {
-            NonNull::new_unchecked(self.as_ptr() as *mut U)
-        }
+        unsafe { NonNull::new_unchecked(self.as_ptr() as *mut U) }
     }
 }
 
@@ -146,13 +140,13 @@ impl<T: ?Sized> Clone for NonNull<T> {
 }
 
 #[stable(feature = "nonnull", since = "1.25.0")]
-impl<T: ?Sized> Copy for NonNull<T> { }
+impl<T: ?Sized> Copy for NonNull<T> {}
 
 #[unstable(feature = "coerce_unsized", issue = "27732")]
-impl<T: ?Sized, U: ?Sized> CoerceUnsized<NonNull<U>> for NonNull<T> where T: Unsize<U> { }
+impl<T: ?Sized, U: ?Sized> CoerceUnsized<NonNull<U>> for NonNull<T> where T: Unsize<U> {}
 
 #[unstable(feature = "dispatch_from_dyn", issue = "0")]
-impl<T: ?Sized, U: ?Sized> DispatchFromDyn<NonNull<U>> for NonNull<T> where T: Unsize<U> { }
+impl<T: ?Sized, U: ?Sized> DispatchFromDyn<NonNull<U>> for NonNull<T> where T: Unsize<U> {}
 
 #[stable(feature = "nonnull", since = "1.25.0")]
 impl<T: ?Sized> fmt::Debug for NonNull<T> {
diff --git a/src/libcore/ptr/unique.rs b/src/libcore/ptr/unique.rs
index 11a3aed1ab4..546b7c9d777 100644
--- a/src/libcore/ptr/unique.rs
+++ b/src/libcore/ptr/unique.rs
@@ -1,8 +1,8 @@
 use crate::convert::From;
-use crate::ops::{CoerceUnsized, DispatchFromDyn};
 use crate::fmt;
 use crate::marker::{PhantomData, Unsize};
 use crate::mem;
+use crate::ops::{CoerceUnsized, DispatchFromDyn};
 use crate::ptr::NonNull;
 
 // ignore-tidy-undocumented-unsafe
@@ -27,9 +27,12 @@ use crate::ptr::NonNull;
 ///
 /// Unlike `*mut T`, `Unique<T>` is covariant over `T`. This should always be correct
 /// for any type which upholds Unique's aliasing requirements.
-#[unstable(feature = "ptr_internals", issue = "0",
-           reason = "use `NonNull` instead and consider `PhantomData<T>` \
-                     (if you also use `#[may_dangle]`), `Send`, and/or `Sync`")]
+#[unstable(
+    feature = "ptr_internals",
+    issue = "0",
+    reason = "use `NonNull` instead and consider `PhantomData<T>` \
+              (if you also use `#[may_dangle]`), `Send`, and/or `Sync`"
+)]
 #[doc(hidden)]
 #[repr(transparent)]
 #[rustc_layout_scalar_valid_range_start(1)]
@@ -48,14 +51,14 @@ pub struct Unique<T: ?Sized> {
 /// unenforced by the type system; the abstraction using the
 /// `Unique` must enforce it.
 #[unstable(feature = "ptr_internals", issue = "0")]
-unsafe impl<T: Send + ?Sized> Send for Unique<T> { }
+unsafe impl<T: Send + ?Sized> Send for Unique<T> {}
 
 /// `Unique` pointers are `Sync` if `T` is `Sync` because the data they
 /// reference is unaliased. Note that this aliasing invariant is
 /// unenforced by the type system; the abstraction using the
 /// `Unique` must enforce it.
 #[unstable(feature = "ptr_internals", issue = "0")]
-unsafe impl<T: Sync + ?Sized> Sync for Unique<T> { }
+unsafe impl<T: Sync + ?Sized> Sync for Unique<T> {}
 
 #[unstable(feature = "ptr_internals", issue = "0")]
 impl<T: Sized> Unique<T> {
@@ -71,9 +74,7 @@ impl<T: Sized> Unique<T> {
     // FIXME: rename to dangling() to match NonNull?
     #[inline]
     pub const fn empty() -> Self {
-        unsafe {
-            Unique::new_unchecked(mem::align_of::<T>() as *mut T)
-        }
+        unsafe { Unique::new_unchecked(mem::align_of::<T>() as *mut T) }
     }
 }
 
@@ -128,9 +129,7 @@ impl<T: ?Sized> Unique<T> {
     /// Casts to a pointer of another type.
     #[inline]
     pub const fn cast<U>(self) -> Unique<U> {
-        unsafe {
-            Unique::new_unchecked(self.as_ptr() as *mut U)
-        }
+        unsafe { Unique::new_unchecked(self.as_ptr() as *mut U) }
     }
 }
 
@@ -143,13 +142,13 @@ impl<T: ?Sized> Clone for Unique<T> {
 }
 
 #[unstable(feature = "ptr_internals", issue = "0")]
-impl<T: ?Sized> Copy for Unique<T> { }
+impl<T: ?Sized> Copy for Unique<T> {}
 
 #[unstable(feature = "ptr_internals", issue = "0")]
-impl<T: ?Sized, U: ?Sized> CoerceUnsized<Unique<U>> for Unique<T> where T: Unsize<U> { }
+impl<T: ?Sized, U: ?Sized> CoerceUnsized<Unique<U>> for Unique<T> where T: Unsize<U> {}
 
 #[unstable(feature = "ptr_internals", issue = "0")]
-impl<T: ?Sized, U: ?Sized> DispatchFromDyn<Unique<U>> for Unique<T> where T: Unsize<U> { }
+impl<T: ?Sized, U: ?Sized> DispatchFromDyn<Unique<U>> for Unique<T> where T: Unsize<U> {}
 
 #[unstable(feature = "ptr_internals", issue = "0")]
 impl<T: ?Sized> fmt::Debug for Unique<T> {