Correct comments and add changelog entry.

Copyright was added to BitVector.hs and some of the comments referred
to functions they were based on where they should've referred to the
functions themselves, and explained undefined mask digits either
ambiguously or just incorrectly.

CHANGELOG.md

@@ -2,6 +2,7 @@
 ## 1.6.4 *Aug 30th 2022*
 Fixed:
 
+ * Add hex and octal BitVector parsing. [#1772] (https://github.com/clash-lang/clash-compiler/pull/2505)
  * Input validation of the used arguments in blackboxes is now complete. [#2184](https://github.com/clash-lang/clash-compiler/pull/2184)
  * `Clash.Annotations.BitRepresentation.Deriving.deriveAnnotation` no longer has quadratic complexity in the size of the constructors and fields. [#2209](https://github.com/clash-lang/clash-compiler/pull/2209)
  * Fully resolve type synonyms when deriving bit representations. [#2209](https://github.com/clash-lang/clash-compiler/pull/2209)

clash-prelude/src/Clash/Sized/Internal/BitVector.hs

@@ -3,6 +3,7 @@ Copyright  :  (C) 2013-2016, University of Twente,
                   2019     , Gergő Érdi
                   2016-2019, Myrtle Software Ltd,
                   2021-2022, QBayLogic B.V.
+                  2023     , Nadia Chambers
 License    :  BSD2 (see the file LICENSE)
 Maintainer :  QBayLogic B.V. <devops@qbaylogic.com>
 -}
@@ -544,7 +545,7 @@ read# cs0 = (fromIntegral (length cs1), BV m v)
 -- >>> $(hLit "dead")
 -- 0b1101111010101101
 --
--- Don't care digits are interpreted as f as a hexadecimal digit.
+-- Don't care digits set 4 bits in the undefined mask.
 hLit :: String -> ExpQ
 hLit s = pure (SigE body typ)
   where
@@ -571,10 +572,10 @@ read16# cs0 = (fromIntegral $ 4 * length cs1, BV m v)
              ++ show c ++ " in input: " ++ cs0
 
 -- | Create an octal literal.
--- >>> $(hLit "5234")
+-- >>> $(oLit "5234")
 -- 0b101011010100
 --
--- Don't care digits are interpreted as 7 as an octal digit.
+-- Don't care digits set 3 bits in the undefined mask.
 oLit :: String -> ExpQ
 oLit s = pure (SigE body typ)
   where