Revert "Fix charWidth for combining characters."

This reverts commit 01d52b4.

src/Text/DocLayout.hs

@@ -94,8 +94,7 @@ import Control.Monad
 import Control.Monad.State.Strict
 import GHC.Generics
 import Data.Bifunctor (second)
-import Data.Char (isSpace, ord,
-                  generalCategory, GeneralCategory(NonSpacingMark))
+import Data.Char (isSpace, ord)
 import Data.List (foldl', intersperse)
 import qualified Data.IntMap.Strict as IM
 import qualified Data.Map.Strict as M
@@ -712,10 +711,7 @@ doubleQuotes = inside (char '"') (char '"')
 -- character, 1 for a regular character, 2 for an East Asian wide character.
 -- Ambiguous characters are treated as width 1.
 charWidth :: Char -> Int
-charWidth c
-  | generalCategory c == NonSpacingMark = 0
-  | otherwise = extractLength .
-                updateMatchStateNarrow (MatchState False 0 ' ' 0) $ c
+charWidth = extractLength . updateMatchStateNarrow (MatchState False 0 ' ' 0)
 
 -- | Get real length of string, taking into account combining and double-wide
 -- characters. Ambiguous characters are treated as width 1.