This commit switches the approach with which we run the ABI analyses: we
now run them until we reach a fixed point. This enables proper
interprocedural propagation of arguments and return values.
Basically, we now inject reads before call sites, so that, if a function
immediately calls another one, the arguments of the callee are
propagated to the caller.
This commit also updates the logic with which we propagate function
prototypes (and names) to callers. The main advantage of this, is that
function wrappers (in particular, PLT entries) now have the same name as
the function they wrap.