[PATCH, MIPS] Fix typo in N64 PLT stub

[Maciej W. Rozycki]

On Sun, 13 Nov 2011, Richard Sandiford wrote:

> > Now, I imagine you would ask why is there a 64-bit address in the PLT
> > resolver that only works with 32-bit symbols (aka -msym32).
> 
> Nah :-)  The PLT's obviously wrong.  Probably a pasto from the n32 version.
> 
> Patch is OK, thanks.  Branch too please, although Tristan plans to
> release 2.22 this coming week.

 For the avoidance of someone's future confusion -- yes, we all know these 
subtle details, but there are mere mortals out there too ;) -- I'd suggest 
updating the comment like:

# 32-bit move (addu)
# 64-bit move (daddu)

or maybe even:

# 32-bit move (addu $15, $31, $0)
# 64-bit move (daddu $15, $31, $0)

What do you think?

  Maciej