hyphen-cased event listeners are unknown when emit key is hyphen-cased

[henribru]

This component defines two emits, one hyphen-cased and one camel-cased: https://github.com/henribru/volar-emit-bug/blob/master/src/components/HelloWorld.vue#L12-L19

This component listens to both emits with hyphen-cased listeners: https://github.com/henribru/volar-emit-bug/blob/master/src/App.vue. The issue is that @foo-bar gets inferred as unknown, while @foo-baz gets inferred correctly. If I change the emit key for foo-bar to fooBar it works as well, so the combination of hyphen-cased emit key and hyphen-cased event listener seems to be broken.