Fix caching of regex highlighter matches
Fix caching of regex highlighter matches

The previous method was constantly invalidating cache when used in
conjunction with region highlighters.

casimir/kakoune,danr/kakoune,jkonecny12/kakoune,ekie/kakoune,Asenar/kakoune,jkonecny12/kakoune,elegios/kakoune,Somasis/kakoune,lenormf/kakoune,mawww/kakoune,occivink/kakoune,ekie/kakoune,flavius/kakoune,lenormf/kakoune,alexherbo2/kakoune,xificurC/kakoune,alexherbo2/kakoune,rstacruz/kakoune,alpha123/kakoune,danielma/kakoune,jkonecny12/kakoune,alpha123/kakoune,jjthrash/kakoune,rstacruz/kakoune,jjthrash/kakoune,zakgreant/kakoune,alpha123/kakoune,rstacruz/kakoune,mawww/kakoune,xificurC/kakoune,xificurC/kakoune,ekie/kakoune,ekie/kakoune,rstacruz/kakoune,jkonecny12/kakoune,elegios/kakoune,alexherbo2/kakoune,mawww/kakoune,xificurC/kakoune,alexherbo2/kakoune,alpha123/kakoune,danielma/kakoune,occivink/kakoune,casimir/kakoune,occivink/kakoune,zakgreant/kakoune,flavius/kakoune,flavius/kakoune,mawww/kakoune,danr/kakoune,flavius/kakoune,Somasis/kakoune,elegios/kakoune,Somasis/kakoune,casimir/kakoune,lenormf/kakoune,Asenar/kakoune,danielma/kakoune,Asenar/kakoune,danr/kakoune,zakgreant/kakoune,occivink/kakoune,danielma/kakoune,lenormf/kakoune,elegios/kakoune,Somasis/kakoune,Asenar/kakoune,casimir/kakoune,jjthrash/kakoune,zakgreant/kakoune,danr/kakoune,jjthrash/kakoune