auto merge of #17227 : tshepang/rust/stronger-break, r=aturon

Remove trailing whitespace while at it

src/doc/guide.md

@@ -4273,7 +4273,7 @@ very common with iterators: we can ignore unnecessary bounds checks, but still
 know that we're safe.
 
 There's another detail here that's not 100% clear because of how `println!`
-works. `num` is actually of type `&int`, that is, it's a reference to an `int`,
+works. `num` is actually of type `&int`. That is, it's a reference to an `int`,
 not an `int` itself. `println!` handles the dereferencing for us, so we don't
 see it. This code works fine too: