Post.fast_count: skip alias normalization.

Post.fast_count calls Tag.normalize_query to normalize the tag string
used for the pfc cache key. This slightly improves cache sharing at the
expense of an extra query during tag searches. The extra query isn't
worth it.

app/models/post.rb

@@ -1111,7 +1111,7 @@ class Post < ApplicationRecord
       tags = tags.to_s
       tags += " rating:s" if CurrentUser.safe_mode?
       tags += " -status:deleted" if CurrentUser.hide_deleted_posts? && !Tag.has_metatag?(tags, "status", "-status")
-      tags = Tag.normalize_query(tags)
+      tags = Tag.normalize_query(tags, normalize_aliases: false)
 
       # optimize some cases. these are just estimates but at these
       # quantities being off by a few hundred doesn't matter much

app/models/tag.rb

@@ -272,10 +272,10 @@ class Tag < ApplicationRecord
       query.to_s.gsub(/\u3000/, " ").strip
     end
 
-    def normalize_query(query, sort: true)
+    def normalize_query(query, normalize_aliases: true, sort: true)
       tags = Tag.scan_query(query.to_s)
       tags = tags.map { |t| Tag.normalize_name(t) }
-      tags = TagAlias.to_aliased(tags)
+      tags = TagAlias.to_aliased(tags) if normalize_aliases
       tags = tags.sort if sort
       tags = tags.uniq
       tags.join(" ")