Round-robin TCG is calling into cpu_exit() directly. In preparation
for making cpu_exit() usable from all accelerators, define a generic
thread-kick function for TCG which is used directly in the multi-threaded
case, and through CPU_FOREACH in the round-robin case.
Use it also for user-mode emulation, and take the occasion to move
the implementation to accel/tcg/user-exec.c.
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>