[javascript mode] Fix potentially-exponential regexp
[javascript mode] Fix potentially-exponential regexp

wingify/CodeMirror,wingify/CodeMirror,nightwing/CodeMirror,pabloferz/CodeMirror,dperetti/CodeMirror,wingify/CodeMirror,nightwing/CodeMirror,hackmdio/CodeMirror,dperetti/CodeMirror,dperetti/CodeMirror,hackmdio/CodeMirror,hackmdio/CodeMirror,pabloferz/CodeMirror,pabloferz/CodeMirror,nightwing/CodeMirror