Ensuring the target is halted when gdb connects.
Ensuring the target is halted when gdb connects.

If gdb connected to a running target, it gets confused and doesn't let
you halt.

mbedmicro/pyOCD,flit/pyOCD,mesheven/pyOCD,mesheven/pyOCD,pyocd/pyOCD,mbedmicro/pyOCD,mesheven/pyOCD,flit/pyOCD,pyocd/pyOCD,mbedmicro/pyOCD