Kakoune: SQL syntax highlighting broken for function invocation.

[johnisom]

Steps

1. Create a SQL file with this content:
   sql SELECT NOW(); SELECT foo FROM bar;
2. Open up the file in Kakoune with syntax highlighting for sql filetype enabled.

Outcome

After the first function invocation of NOW(), all regular text that shouldn't be highlighted (in this case foo and bar) is turned grey (or a different color other than white/the default).
See screenshot:

Expected

I would expect that the grey (or other color depending on colorscheme) color would only be limited to the NOW() text and not any of the regular statements after it that are unworthy of being highlighted. This is what normal highlighting with the Mysticaltutor theme looks like:

Notes

• With other color schemes the contrast is much more stark. Compare the two:
  
  
• If a string is given as an argument to the function then the function highlighting doesn't work at all:
  

[johnisom]

Unless someone is leaping for joy at the opportunity to take this one, I'll go ahead and submit a PR for it this week.