8-byte register values on a 32-bit machine

[Andrew Cagney]

> mec> The general case of 2-word structures in 5.3 was broken.  That is to say,
> mec> my simple test program (attached to the PR) fails with both 5.3 and HEAD.
> 
> ac> I386 or general?  To the best of my knowledge, structs worked on 
> ac> non-i386 architectures.
> 
> Native i686-pc-linux-gnu.

Right, so it can't be assumed that `the general case of 2-word structs 
in 5.3 was broken'.

> I just tested on native sparc-sun-solaris2.7, but the only compiler
> I have, gcc 3.2.2, does not put the 2-word structure into registers.

Thanks for clarifying this,
Andrew