Interrupt classes: _NTO_TRACE_INTENTER, _NTO_TRACE_INTEXIT, _NTO_TRACE_INT_HANDLER_ENTER, and _NTO_TRACE_INT_HANDLER

These classes track interrupts.

Class	traceprinter label	IDE label	Emitted when:
_NTO_TRACE_INTENTER	`INT_ENTR`	`Entry`	Overall processing of an interrupt begins
_NTO_TRACE_INTEXIT	`INT_EXIT`	`Exit`	Overall processing of an interrupt ends
_NTO_TRACE_INT_HANDLER_ENTER	`INT_HANDLER_ENTR`	`Handler Entry`	Entering an interrupt handler
_NTO_TRACE_INT_HANDLER_EXIT	`INT_HANDLER_EXIT`	`Handler Exit`	Exiting an interrupt handler

The expected sequence is:

INTR_ENTER
    INTR_HANDLER_ENTER
    INTR_HANDLER_EXIT
    INTR_HANDLER_ENTER
    INTR_HANDLER_EXIT
INT_EXIT

_NTO_TRACE_INT is a pseudo-class that comprises all of the interrupt classes.

The "event" is an interrupt vector number, in the range from _NTO_TRACE_INTFIRST through _NTO_TRACE_INTLAST.

Interrupt classes: _NTO_TRACE_INTENTER, _NTO_TRACE_INTEXIT, _NTO_TRACE_INT_HANDLER_ENTER, and _NTO_TRACE_INT_HANDLER_EXIT