cpu-timers, icount: new modules

refactoring of cpus.c continues with cpu timer state extraction.

cpu-timers: responsible for the softmmu cpu timers state,
            including cpu clocks and ticks.

icount: counts the TCG instructions executed. As such it is specific to
the TCG accelerator. Therefore, it is built only under CONFIG_TCG.

One complication is due to qtest, which uses an icount field to warp time
as part of qtest (qtest_clock_warp).

In order to solve this problem, provide a separate counter for qtest.

This requires fixing assumptions scattered in the code that
qtest_enabled() implies icount_enabled(), checking each specific case.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[remove redundant initialization with qemu_spice_init]
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
[fix lingering calls to icount_get]
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

util/main-loop.c

@@ -27,7 +27,7 @@
 #include "qemu/cutils.h"
 #include "qemu/timer.h"
 #include "sysemu/qtest.h"
-#include "sysemu/cpus.h"
+#include "sysemu/cpu-timers.h"
 #include "sysemu/replay.h"
 #include "qemu/main-loop.h"
 #include "block/aio.h"
@@ -521,9 +521,13 @@ void main_loop_wait(int nonblocking)
     mlpoll.state = ret < 0 ? MAIN_LOOP_POLL_ERR : MAIN_LOOP_POLL_OK;
     notifier_list_notify(&main_loop_poll_notifiers, &mlpoll);
 
-    /* CPU thread can infinitely wait for event after
-       missing the warp */
-    qemu_start_warp_timer();
+    if (icount_enabled()) {
+        /*
+         * CPU thread can infinitely wait for event after
+         * missing the warp
+         */
+        qemu_start_warp_timer();
+    }
     qemu_clock_run_all_timers();
 }