Syntax highlighting confused by lack of spaces

If I have the following code in a file:

```haskell
bad xs = [x|x <- xs]
good xs = [ x | x <- xs]
```
the syntax highlighting gives up after the first '[x'.

If I remove or comment out 'bad' then it highlights correctly.

Reproduce the issue in haskell-mode with the provided list-comprehension snippet, comparing the versions with and without spaces. Trace the syntax-highlighting path responsible for the first '[x' and verify that highlighting continues through the rest of the file without requiring spaces.

Written by the indexing model from the issue text.