Tweaks around handling of --limit-rate:
* tracing: trace outstanding timeouts by name
* multi: do not mark transfer as dirty that have
an EXPIRE_TOOFAST set
* multi: have one static function to asses speed limits
* multi: when setting EXPIRE_TOOFAST remove the transfers
from the dirty set
* progress: rename vars and comment on how speed limit
timeouts are calculated, for clarity
* transfer: when speed limiting, exit the receive loop
after a quarter of the limit has been received, not
on the first chunk received.
* cf-ip-happy.c: clear EXPIRE_HAPPY_EYEBALLS on connect
* scorecard: add --limit-rate parameter to test with
speed limits in effect
Closes#18454
`getsock()` calls operated on a global limit that could
not be configure beyond 16 sockets. This is no longer adequate
with the new happy eyeballing strategy.
Instead, do the following:
- make `struct easy_pollset` dynamic. Starting with
a minimal room for two sockets, the very common case,
allow it to grow on demand.
- replace all protocol handler getsock() calls with pollsets
and a CURLcode to return failures
- add CURLcode return for all connection filter `adjust_pollset()`
callbacks, since they too can now fail.
- use appropriately in multi.c and multi_ev.c
- fix unit2600 to trigger pollset growth
Closes#18164
When `CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS` expires, start the next ip
connect attempt, but keep all ongoing attempts alive.
Separate happy-eyeballs connection filter into own source files.
Closes#18105
