[Ada] Use no-copy types in the Ada compiler

[Eric Botcazou]

> > +	/* If it is passed by reference, force BLKmode to ensure that objects
> > ++	   of this type will always be put in memory.  */
>
> Typo?

Yes, Laurent Guerby spotted it as well a few hours ago, will fix later.

> Out of curiosity, what's the benefit?

This exposes bugs in the compiler, like the tree-nested.c one which has been 
there since 4.0, as well as inefficiencies like copies of big CONSTRUCTORs.

-- 
Eric Botcazou