replay: check icount in cpu exec loop

This patch adds check to break cpu loop when icount expires without
setting the TB_EXIT_ICOUNT_EXPIRED flag. It happens when there is no
available translated blocks and all instructions were executed.
In icount replay mode unnecessary tb_find will be called (which may
cause an exception) and execution will be non-deterministic.
Because cpu_loop_exec_tb cannot longjmp anymore, we can remove
the anticipated call to align_clocks in cpu_loop_exec_tb, as
well as the SyncClocks *sc argument.

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <002801d2810f$18809c20$4981d460$@ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <dovgaluk@ispras.ru>
