C++: Simplify cpp/certificate-not-checked

[MathiasVP]

The cpp/certificate-not-checked query had two unnecessary complications:

1. It was reinventing the ensuresEqEdge predicate (which existed on the IRGuardCondition, but not in GuardCondition)
2. It had explicit handling of ! and implicit int-to-bool conversions.

This PR fixes both of these problems. (1) is fixed by lifting those ensures*Edge from IRGuardConditions to GuardConditions and use those new predicates in the query. (2) can just be removed because of the earlier work we've done on unary guards.

DCA was uneventful

[Copilot]

Pull Request Overview

This PR simplifies the cpp/certificate-not-checked query by refactoring guard condition handling and removing unnecessary complexity. The changes improve code reuse by lifting predicate functionality from IR-level to AST-level guards and eliminate manual handling of boolean conversions.

• Refactors the certIsZero predicate to use the new ensuresEqEdge predicate instead of manual guard condition logic
• Adds ensures*Edge predicates to GuardCondition class, lifting functionality from IRGuardCondition
• Removes explicit handling of negation operators and implicit int-to-bool conversions

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
cpp/ql/src/Security/CWE/CWE-295/SSLResultNotChecked.ql	Simplifies the certIsZero predicate by replacing complex manual guard logic with a single call to ensuresEqEdge
cpp/ql/lib/semmle/code/cpp/controlflow/IRGuards.qll	Adds new ensures*Edge predicates and valueControlsEdge methods to provide edge-based guard condition analysis at the AST level