accel/tcg: Introduce translator_io_start

New wrapper around gen_io_start which takes care of the USE_ICOUNT
check, as well as marking the DisasContext to end the TB.
Remove exec/gen-icount.h.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
33 files changed