http2: send out pending data earlier
If there’s a lot of data waiting on a given stream, send it out early, if possible. This helps trigger the backpressure mechanism introduced in 8a4a1931 at a better time.
(Will look into writing tests for this.)
Checklist
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make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
tests and/or benchmarks are included -
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