Not merging inlines breaks fundec invariant

[sim642]

fundec claims the invariant that the physical objects are in one-to-one correspondence with varinfos:

cil/src/cil.ml

Lines 688 to 694 in c47bbbd

	(** Function definitions. *)
	and fundec =
	{ mutable svar: varinfo;
	(** Holds the name and type as a variable, so we can refer to it
	* easily from the program. All references to this function either
	* in a function call or in a prototype must point to the same
	* varinfo. *)

And Goblint relies on this invariant by identifying functions by the underlying variable (ID).

In goblint/analyzer#603 (comment), I realized that #72 broke this invariant.
This is also easily seen in the code:

cil/src/mergecil.ml

Lines 1421 to 1425 in c47bbbd

	| GFun (fdec, l) as g ->
	currentLoc := l;
	incr currentDeclIdx;
	(* We apply the renaming *)
	fdec.svar <- processVarinfo fdec.svar l;

where the underlying variable is replaced unconditionally (of merge_inlines).

[stilscher]

What do you mean with physical object? The invariant just says, that all references to a function must point to the same varinfo. So different instances of a function (for example two instances of a static inline function that has not been merged) could still have different varinfos as long as they are consistent with the respective function calls, right?