[PATCH] x86-64: Fix interrupt race in idle callback (3rd try)
Idle callbacks has some races when enter_idle() sets isidle and subsequent
interrupts that can happen on that CPU, before CPU goes to idle. Due to this,
an IDLE_END can get called before IDLE_START. To avoid these races, disable
interrupts before enter_idle and make sure that all idle routines do not
enable interrupts before entering idle.
Note that poll_idle() still has a this race as it has to enable interrupts
before going to idle. But, all other idle routines have the race fixed.