[javascript mode] Fix bug in object literal spread parsing
[javascript mode] Fix bug in object literal spread parsing

Closes #5036

dperetti/CodeMirror,SidPresse/CodeMirror,pabloferz/CodeMirror,namin/CodeMirror,wingify/CodeMirror,pabloferz/CodeMirror,thomasjm/CodeMirror,codio/CodeMirror,notepadqq/CodeMirror,namin/CodeMirror,jayaprabhakar/CodeMirror,ficristo/CodeMirror,hackmdio/CodeMirror,ficristo/CodeMirror,jayaprabhakar/CodeMirror,wingify/CodeMirror,jkaplon/CodeMirror,jkaplon/CodeMirror,notepadqq/CodeMirror,dperetti/CodeMirror,SidPresse/CodeMirror,notepadqq/CodeMirror,codio/CodeMirror,hackmdio/CodeMirror,namin/CodeMirror,nightwing/CodeMirror,ficristo/CodeMirror,pabloferz/CodeMirror,wingify/CodeMirror,mtaran-google/CodeMirror,hackmdio/CodeMirror,mtaran-google/CodeMirror,nightwing/CodeMirror,jayaprabhakar/CodeMirror,mtaran-google/CodeMirror,nightwing/CodeMirror,thomasjm/CodeMirror,dperetti/CodeMirror,codio/CodeMirror,thomasjm/CodeMirror,SidPresse/CodeMirror,jkaplon/CodeMirror