[switch_to_task] Remove the irq_clear_mask(X86_PC_TIMER_IRQ)
[switch_to_task] Remove the irq_clear_mask(X86_PC_TIMER_IRQ)

Reason: now handle_irq() never masks IRQ 0.

vvaltchev/experimentOs,vvaltchev/experimentOs,vvaltchev/experimentOs,vvaltchev/experimentOs