[Path,AVR]: Improve loading of 32-bit constants

[Georg-Johann Lay]

Denis Chertykov wrote:
> I have asked about example of *d instead of !d.
> Just svn GCC with *d vs svn GCC !d.
> 
> Denis.

Is the patch ok with the original !d instead of *d ?
It still improves and the !d vs. *d don't matter because there's
always r I think.

Johann