Infrastructure to let ipcp to remove unused arguments from calls

[Jan Hubicka]

> > On Wed, Aug 27, 2008 at 11:39, Jan Hubicka <jh@suse.cz> wrote:
> > 
> > > +
> > > +  /* This is a new type, not a copy of an old type.  Need to reassociate
> > > +     variants.  We can handle everything except the main variant lazily.  */
> > > +  t = TYPE_MAIN_VARIANT (orig_type);
> > 
> > Why not use build_variant_type_copy() here?
> 
> I didn't noticed existence of this function so far ;).  The variant handling
> is copied from type duplication in tree-inline. 
> 
> In meantime I however noticed problem with java, where constant
> propagating THIS pointer to method (that happens quite often in libjava
> build with clonning) confuse debug output as METHOD_TYPE is supposed to
> always have THIS pointer as first operand.
> 
> I think I need to translate the type to FUNCTION_TYPE and I guess only
> way is to build type from scratch via build_function_type.
> 
> This is patch I tested in meantime (+the renaming), I guess
> build_variant_type_copy does not give us much benefit here...

Forgot to add, bootstrapped/regtested x86_64-linux with wnd without ipcp
patch, OK? :)

Honza