[PATCH, RFC] LRA subreg handling

[Robert Suchanek]

> Robert, can you look at reload.c::reload_inner_reg_of_subreg and verify
> that the comment just before its return statement is effectively the
> situation you're in.
> 
> There are certainly cases where a SUBREG needs to be treated as an
> in-out operand.  We walked through them eons ago when we were poking at
> SSA for RTL.  But the details have long since faded from memory.

The comment pretty much applies to my situation.  The only difference I can
see is that reload would have had hard registers at this point.  In the testcase,
LRA does not have hard registers assigned to the concerned pseudo(s), thus, 
it can't rely on the information in hard_regno_nregs to check if the number of
registers in INNER is different to the number of words in INNER.

Robert