Morsel.__init__ loops reserved values and could be replaced with a simple dict update #126156
Description
Line 276 in 224c370
Backstory:
aio-libs/aiohttp#9594
Processing cookies is a significant part of the aiohttp request time, and some requesters have to create many Morsel objects because they have a lot of cookies on every request.
There are few places that can be optimized in http.cookies
This one is low hanging fruit