remote bitbang performance loss

[Tim N. <ti...@si...>]

Change
https://sourceforge.net/p/openocd/code/ci/7dd323b26d93e49e409e02053e30f53ac8138cd5/
cut remote bitbang performance (when talking to the spike RISC-V simulator)
approximately in half. This change "removes the file write stream, replaces
it with socket write calls." Previously performance was better because the
individual byte-size writes were buffered, and didn't result in a system
call until fflush() was called.

I assume the right way to fix this is to implement a buffer/flush mechanism
inside OpenOCD, on top of the socket calls, so that the optimization also
works on Windows. Is that right? Is anybody motivated to take that on?

Tim