With this patch QEMU handles qAttached request from gdb. When QEMU
replies 1, GDB sends a "detach" command at the end of a debugging
session otherwise GDB sends "kill".
The default value for qAttached is 1 on system emulation and 0 on user
emulation.
Based on original version by Fabien Chouteau.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>