Use return type as an inference location #11152

From #11054

interface FolderContentItem{
    type: 'folder' | 'file';
}

let a:FolderContentItem[] = [];
a = [1,2,3,4,5].map(v=>({type:'folder'}))

Today this is an error without casting "folder" to the literal type. We have a contextual type coming from a that is not being used.