kdb: add rdmsr and wrmsr commands for i386

[Mitch Bradley]

Bernardo Innocenti wrote:
> Mitch Bradley wrote:
>
>   
>> If it wouldn't be too difficult, it would also be nice to permit 
>> embedded commas or dots in the number, because counting digits in a 
>> 64-bit number is very difficult without the help of punctuation.
>>     
>
> It is customary to use _ for this purpose: 0x01234567_89ABCDEF.
>   

_ is okay with me.  I don't really care what the delimiter characters 
is, just that it is possible to have one.

> Some people even break it in 16bit words, but it seems overkill
> to me.
>
>