[lldb/gdb-remote] Remove initial pipe-draining workaround

This code, added in rL197579 (Dec 2013) is supposed to work around what
was presumably a qemu bug, where it would send unsolicited stop-reply
packets after the initial connection.

At present, qemu does not exhibit such behavior. Also, the 10ms delay
introduced by this code is sufficient to mask bugs in other stubs, but
it is not sufficient to *reliably* mask those bugs. This resulted in
flakyness in one of our stubs, which was (incorrectly) sending a +
packet at the start of the connection, resulting in a small-but-annoying
number of dropped connections.

Differential Revision: https://reviews.llvm.org/D114529

GitOrigin-RevId: a6fedbf20c8f87061f333169120790e2c6f22806
1 file changed