possible readability improvement for i386 pcpu macros:

[John Baldwin]

On Sunday 02 August 2009 6:23:26 am Julian Elischer wrote:
> 
> if you have to ever look at the output of the cpp then this removes a 
> number of things you have to puzzle over in the output of PCPU_SET()
> and friends.
> 
> 
> I don't know if it applies to the other architectures.

It probably applies to amd64.  Also, simplifying the amount of code the macros 
generate can reduce compile time.  That is why Peter added __curthread() so 
that all the curthread references did not have to compile a fully expanded 
PCPU_GET() macro each time.  It gave a noticable reduction in kernel compile 
time.

-- 
John Baldwin