C++: Fix bad magic.

Author: MathiasVP

cpp/ql/lib/semmle/code/cpp/security/Overflow.qll

@@ -25,6 +25,7 @@ predicate guardedAbs(Operation e, Expr use) {
  * Holds if the value of `use` is guarded to be less than something, and `e`
  * is in code controlled by that guard (where the guard condition held).
  */
+pragma[nomagic]
 predicate guardedLesser(Operation e, Expr use) {
   exists(GuardCondition c | c.ensuresLt(use, _, _, e.getBasicBlock(), true))
   or
@@ -35,6 +36,7 @@ predicate guardedLesser(Operation e, Expr use) {
  * Holds if the value of `use` is guarded to be greater than something, and `e`
  * is in code controlled by that guard (where the guard condition held).
  */
+pragma[nomagic]
 predicate guardedGreater(Operation e, Expr use) {
   exists(GuardCondition c | c.ensuresLt(use, _, _, e.getBasicBlock(), false))
   or