Re-submitted as a separate patch.

The problem: small structs returned in one (or two) registers
are aligned left in N32/N64 and aligned right in the others
(or vice versa, depending on how you cross your eyes).



There are two code paths here, one for structs of length < MIPS_REGSIZE, 
and one for MIPS_REGSIZE < struct len < 2 * MIPS_REGSIZE.

The first case I've split into two paths: one for N32 &&
TYPE_CODE_STRUCT, 
and a second for everything else (the later being identical to what was
there before).

In the second case, I've simply let the N32/N64 path fall thru.
The next "if" catches it and handles it correctly.