INT 15 - Advanced Power Management Specification - SYSTEM STAND-BY
        AX = 5307h
        BX = 0001h
        CX = 0001h
Return: CF clear
Notes:  puts the entire system into stand-by mode; normally called in response
          to a System Stand-by Request notification after any necessary
          processing, but may also be invoked at the caller's discretion
        should not be called from within a hardware interrupt handler to avoid
          reentrance problems
        the stand-by state is typically exited on an interrupt
SeeAlso: AX=4280h,AX=5307h/BX=0001h/CX=0002h,AX=530Bh

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