Auto merge of #55974 - pietroalbini:rollup, r=pietroalbini

Rollup of 17 pull requests

Successful merges:

 - #55182 (Redox: Update to new changes)
 - #55211 (Add BufWriter::buffer method)
 - #55507 (Add link to std::mem::size_of to size_of intrinsic documentation)
 - #55530 (Speed up String::from_utf16)
 - #55556 (Use `Mmap` to open the rmeta file.)
 - #55622 (NetBSD: link libstd with librt in addition to libpthread)
 - #55750 (Make `NodeId` and `HirLocalId` `newtype_index`)
 - #55778 (Wrap some query results in `Lrc`.)
 - #55781 (More precise spans for temps and their drops)
 - #55785 (Add mem::forget_unsized() for forgetting unsized values)
 - #55852 (Rewrite `...` as `..=` as a `MachineApplicable` 2018 idiom lint)
 - #55865 (Unix RwLock: avoid racy access to write_locked)
 - #55901 (fix various typos in doc comments)
 - #55926 (Change sidebar selector to fix compatibility with docs.rs)
 - #55930 (A handful of hir tweaks)
 - #55932 (core/char: Speed up `to_digit()` for `radix <= 10`)
 - #55956 (add tests for some fixed ICEs)

Failed merges:

r? @ghost

3 files changed, 11 insertions, 3 deletions

diff --git a/src/liballoc/collections/btree/node.rs b/src/liballoc/collections/btree/node.rs
index deca9591fbd..f9b455fe796 100644
--- a/src/liballoc/collections/btree/node.rs
+++ b/src/liballoc/collections/btree/node.rs
@@ -69,7 +69,7 @@ struct LeafNode<K, V> {
 
     /// This node's index into the parent node's `edges` array.
     /// `*node.parent.edges[node.parent_idx]` should be the same thing as `node`.
-    /// This is only guaranteed to be initialized when `parent` is nonnull.
+    /// This is only guaranteed to be initialized when `parent` is non-null.
     parent_idx: MaybeUninit<u16>,
 
     /// The number of keys and values this node stores.
diff --git a/src/liballoc/raw_vec.rs b/src/liballoc/raw_vec.rs
index 837770feece..e87bf78561c 100644
--- a/src/liballoc/raw_vec.rs
+++ b/src/liballoc/raw_vec.rs
@@ -44,7 +44,7 @@ use boxed::Box;
 /// This enables you to use capacity growing logic catch the overflows in your length
 /// that might occur with zero-sized types.
 ///
-/// However this means that you need to be careful when roundtripping this type
+/// However this means that you need to be careful when round-tripping this type
 /// with a `Box<[T]>`: `cap()` won't yield the len. However `with_capacity`,
 /// `shrink_to_fit`, and `from_box` will actually set RawVec's private capacity
 /// field. This allows zero-sized types to not be special-cased by consumers of
diff --git a/src/liballoc/string.rs b/src/liballoc/string.rs
index 2beb3240aac..8d009101ce7 100644
--- a/src/liballoc/string.rs
+++ b/src/liballoc/string.rs
@@ -618,7 +618,15 @@ impl String {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn from_utf16(v: &[u16]) -> Result<String, FromUtf16Error> {
-        decode_utf16(v.iter().cloned()).collect::<Result<_, _>>().map_err(|_| FromUtf16Error(()))
+        let mut ret = String::with_capacity(v.len());
+        for c in decode_utf16(v.iter().cloned()) {
+            if let Ok(c) = c {
+                ret.push(c);
+            } else {
+                return Err(FromUtf16Error(()));
+            }
+        }
+        Ok(ret)
     }
 
     /// Decode a UTF-16 encoded slice `v` into a `String`, replacing