Byte string literals are now fixed-size arrays

Changed in rust-lang#22838.

audited (raw) byte string literals @ rust-lang#16676

Author: nwin

reference.md

@@ -281,7 +281,7 @@ preceded by the characters `U+0062` (`b`) and `U+0022` (double-quote), and
 followed by the character `U+0022`. If the character `U+0022` is present within
 the literal, it must be _escaped_ by a preceding `U+005C` (`\`) character.
 Alternatively, a byte string literal can be a _raw byte string literal_, defined
-below. A byte string literal is equivalent to a `&'static [u8]` borrowed array
+below. A byte string literal of length `n` is equivalent to a `&'static [u8; n]` borrowed fixed-sized array
 of unsigned 8-bit integers.
 
 Some additional _escapes_ are available in either byte or non-raw byte string