[Ohrrpgce] I declare a vendetta against BYREF

[Ralph Versteegen]

I am now sure that defaulting to BYREF is pure evil, and we should
make OPTION BYVAL a priority. Plus, I'm getting sick of typing
hundreds of explicit BYVALs.

Examine the following (not quite yet committed) code, which has
prevented me from getting anything done today:

declare sub dlist_remove (byref this as DoubleList(Any), byval item as any ptr)
...
SUB remove_menu_item(BYREF menu AS MenuDef, mi AS MenuDefItem ptr)
 dlist_remove menu.itemlist, mi
 DELETE mi
 'rebuild menu.items[]
 SortMenuItems menu
END SUB
...
remove_menu_item menudata, menudata.last

So where's the problem? dlist_remove is changing the value of mi,
causing the wrong menu item to be deleted. How can that be?
menudata.last is modified inside dlist_remove, and it's been passed by
reference. This is kind of like the normal behaviour of byref in
reverse; the passed value in a way is being modified by the calling
function during the execution of the callee. Incidentally, the
possibility of this kind of pointer insanity is a huge problem for the
optimisation of C code.