forked from Imagelibrary/rtems
* shared/irq/openpic_i8259_irq.c: - conditionally define 'irq_mask_or_tbl' only if BSP_PCI_ISA_BRIDGE_IRQ is defined. - use _ISR_Get_level() / _ISR_Set_level() for re-enabling interrupts rather than messing with MSR directly; these macros: o implement compiler memory barrier o will handle multiple levels (e500 'critical' interrupts) if they are ever supported. - decrementer irqs are also shareable - added list traversal.