[PATCH/RFC/RFA] Print in-memory struct return values

[Andrew Cagney]

Ouch.  That's really ugly.  I thought RETURN_VALUE_STRUCT_CONVENTION
was already long enough.  I'd really like to avoid thos really long
names.  Hmm what if I use:
RETURN_VALUE_ABI_RETURNS_ADDRESS
RETURN_VALUE_ABI_PRESERVES_ADDRESS
yes.

Andrew