C/C++: Disable constant folding of address-vs-null comparisons

Author: IdrissRio

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedElement.qll

@@ -68,6 +68,7 @@ private predicate ignoreConstantValue(Operation op) {
  * means to express those as QL values.
  */
 predicate isIRConstant(Expr expr) {
+  not expr = any(IfStmt ifstmt).getCondition().getFullyConverted() and
   exists(expr.getValue()) and
   // We avoid constant folding certain operations since it's often useful to
   // mark one of those as a source in dataflow, and if the operation is