- to read post data of requests, we have to read stream
- to restore the stream later on, we have to rewind it back
- however, if the stream is large enough, it cannot be rewound back
This patch starts cloning post data streams if possible to avoid
back-rewinding them later on.
References #4704
This adds a firefox-stable application to build on our bots.
This is basically a rebaselined version of 66541552d088cc211f170ccc8ea8f0c6bacdb045
The firefox base revision is bb9bf7e886
Which is taken from `about://buildconfig` of a stable Firefox version
on Mac as of Apr 9, 2021.
References #5993
