[Crash-utility] [PATCH v3] add option -s and -S for subcommand irq

[Dave Anderson]

I have verified and applied the "irq -a" and "irq -s" options 
on both IA64 and PPC64.

Both S390 and S390X do not support the "irq" command, so I'll defer
all IRQ-related issues to Michael Holzheu if there's any interest
there.

I tried it on 32-bit PPC, but I don't have an SMP vmcore, so "irq -a"
fails as expected.  And the "irq -s" option fails like so:

  crash> irq -s
             CPU0 
  irq: cannot determine size of irq_desc_t
  crash>

And I note that the basic "irq" command does not work on 32-bit PPC:

  crash> irq
  
  irq: invalid structure size: irqdesc
       FILE: ppc.c  LINE: 1292  FUNCTION: ppc_dump_irq()
  
  [./crash] error trace: 10066230 => 100cb078 => 100e3a68 => 100fc608
  
    100fc608: SIZE_verify+232
    100e3a68: ppc_dump_irq+168
    100cb078: cmd_irq+1960
    10066230: exec_command+960
  
  irq: invalid structure size: irqdesc
       FILE: ppc.c  LINE: 1292  FUNCTION: ppc_dump_irq()
  
  crash>

So I'll defer all PPC "irq" command support to Suzuki or Toshi.

And lastly, many thanks to Zhang Yanfei for implementing these 
two options.

Dave