reaching-defs: don't add reaching definition to constants in undef call
reaching-defs: don't add reaching definition to constants in undef call

if we have call to undefined funciton, we assume that anything we can
pass there via pointer can be defined. But it is not a true for constant
pointers, we cannot define these

Signed-off-by: Marek Chalupa <a05df156a69ad59faa9af9b666ef78009594c145@gmail.com>

mchalupa/dg,mchalupa/dg,mchalupa/dg,mchalupa/dg