Trouble formatting data declaration where there is no space between field name and ::

[andremarianiello]

(moved from haskell/haskell-language-server#4466)

Behavior summary by stylish-haskell version(s):

• 0.14.6.0 - Main.hs: <string>:5:6: error: parse error on input :'`
• 0.13.0.0 - Main.hs: RealSrcSpan SrcSpanOneLine "Main.hs" 5 6 7: parse error on input :'`
• 0.12.0.0 - Main.hs: RealSrcSpan SrcSpanOneLine "Main.hs" 5 6 7: parse error on input :'`
• 0.11.0.0 - Language.Haskell.Stylish.Parse.parseModule: could not parse Main.hs: ParseFailed (SrcLoc "<unknown>.hs" 5 6) "Parse error: :"
• 0.10.0.0 - Successful parse and formatting!

Steps to reproduce

Format
Main.hs:

main = pure ()

data MyRecord = MyRecord
  { ab :: Int
  , c:: Int
  }

with stylish-haskell Main.hs

Important pieces here:

• c:: Int <- no space between field name and ::. This makes the formatting fail.
• ab field name is longer than c field name. This makes the error show up in the LSP log. If the fields are the same length no error appears, but the formatting still fails to apply. Weird!

Expected behaviour

Since this code compiles with ghc Main.hs I would expect it to be formatted with stylish-haskell Main.hs