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.

1 files changed, 6 insertions, 6 deletions

diff --git a/src/libcore/unicode/bool_trie.rs b/src/libcore/unicode/bool_trie.rs
index 39584d346e4..b7fba88a540 100644
--- a/src/libcore/unicode/bool_trie.rs
+++ b/src/libcore/unicode/bool_trie.rs
@@ -19,16 +19,16 @@
 /// non-BMP range of most Unicode sets.
 pub struct BoolTrie {
     // 0..0x800 (corresponding to 1 and 2 byte utf-8 sequences)
-    pub r1: [u64; 32],   // leaves
+    pub r1: [u64; 32], // leaves
 
     // 0x800..0x10000 (corresponding to 3 byte utf-8 sequences)
     pub r2: [u8; 992],      // first level
-    pub r3: &'static [u64],  // leaves
+    pub r3: &'static [u64], // leaves
 
     // 0x10000..0x110000 (corresponding to 4 byte utf-8 sequences)
-    pub r4: [u8; 256],       // first level
-    pub r5: &'static [u8],   // second level
-    pub r6: &'static [u64],  // leaves
+    pub r4: [u8; 256],      // first level
+    pub r5: &'static [u8],  // second level
+    pub r6: &'static [u64], // leaves
 }
 impl BoolTrie {
     pub fn lookup(&self, c: char) -> bool {
@@ -48,7 +48,7 @@ impl BoolTrie {
 
 pub struct SmallBoolTrie {
     pub(crate) r1: &'static [u8],  // first level
-    pub(crate) r2: &'static [u64],  // leaves
+    pub(crate) r2: &'static [u64], // leaves
 }
 
 impl SmallBoolTrie {