Test new filename mappings

[jrieken]

• any OS @bpasero

This is for #1851 which add support for glob patterns when associating filenames to a language (for reference: https://code.visualstudio.com/docs/extensionAPI/extension-points#_contributeslanguages). Make sure that

• you can define a glob pattern, like foo*.bar to associate filenames to a language
• full name matches have higher pro then glob pattern matches, gulpfile.js -> Foo-lang vs gulp*.js -> Bar-lang
• the pattern is only applied to the name not path