Merge branch 'master' into handle-drop-zst

src/races.md

@@ -7,7 +7,7 @@ Safe Rust guarantees an absence of data races, which are defined as:
 * one or more of them is unsynchronized
 
 A data race has Undefined Behavior, and is therefore impossible to perform in
-Safe Rust. Data races are *mostly* prevented through Rust's ownership system:
+Safe Rust. Data races are prevented *mostly* through Rust's ownership system alone:
 it's impossible to alias a mutable reference, so it's impossible to perform a
 data race. Interior mutability makes this more complicated, which is largely why
 we have the Send and Sync traits (see the next section for more on this).

src/what-unsafe-does.md

@@ -41,7 +41,7 @@ language cares about is preventing the following things:
     [`NonNull`] that is null. (Requesting custom invalid values is an unstable
     feature, but some stable libstd types, like `NonNull`, make use of it.)
 
-For a more detailed explanation about "Undefined Bahavior", you may refer to
+For a more detailed explanation about "Undefined Behavior", you may refer to
 [the reference][behavior-considered-undefined].
 
 "Producing" a value happens any time a value is assigned, passed to a