Get Virtual Interrupt State

Returns the current state of the virtual interrupt flag.

Call With:

   AX     = 0902H

Returns:

   Carry flag= clear (this function always succeeds)
   AL     = 0 if virtual interrupts are disabled
          = 1 if virtual interrupts are enabled

Notes:

o  This function should be used in preference to the PUSHF
   instruction to examine the interrupt flag, because the
   PUSHF instruction returns the physical interrupt flag
   rather than the virtualized (per-client) interrupt flag.
   On some DPMI hosts, the physical interrupt flag will
   always be enabled, even when hardware interrupts are not
   being passed through to the client.