[PATCH] The behavior of gas .subsection/.previous does not confirm descriptions in document

[Lee Duhem]

>>         .section sec1
>>         .long 0x11111111
>>
>>         .subsection 1
>>         .long 0x22222222
>>
>>         .pushsection sec2
>>         .subsection 1
>>         .long 0x66666666
>>         .long 0x77777777
>
>
>Here we are in sec2, subsection 1.
>
>>         .subsection 0
>>         .long 0x55555555
>
>Now we are in sec2, subsection 0.
>
>>         .previous
>
>So .previous takes you back to sec2, subsection 1.
>

I think .previous takes me back to sec1 is more natural, because
for current section sec2, sec1 is the previous section(instead of sec2).

But if the behavior of .subsection/.previous is intended, add some examples
in documents maybe helpful.

lee