[javascript mode] Recognize TypeScript-style type parameters for functions
[javascript mode] Recognize TypeScript-style type parameters for functions

Issue #4643

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